Routing, Localization And Positioning Protocols For Wireless Sensor And Actor Networks

Wireless sensor and actor networks (WSANs) are distributed systems of sensor nodes and actors that are interconnected over the wireless medium. Sensor nodes collect information about the physical world and transmit the data to actors by using one-hop or multi-hop communications. Actors collect information from the sensor nodes, process the information, take decisions and react to the events. This dissertation presents contributions to the methods of routing, localization and positioning in WSANs for practical applications. We first propose a routing protocol with service differentiation for WSANs with stationary nodes. In this setting, we also adapt a sports ranking algorithm to dynamically prioritize the events in the environment depending on the collected data. We extend this routing protocol for an application, in which sensor nodes float in a river to gather observations and actors are deployed at accessible points on the coastline. We develop a method with locally acting adaptive overlay network formation to organize the network with actor areas and to collect data by using locality-preserving communication. We also present a multi-hop localization approach for enriching the information collected from the river with the estimated locations of mobile sensor nodes without using positioning adapters. As an extension to this application, we model the movements of sensor nodes by a subsurface meandering current mobility model with random surface motion. Then we adapt the introduced routing and network organization methods to model a complete primate monitoring system. A novel spatial cut-off preferential attachment model and iii center of mass concept are developed according to the characteristics of the primate groups. We also present a role determination algorithm for primates, which uses the collection of spatial-temporal relationships. We apply a similar approach to human social networks to tackle the problem of automatic generation and organization of social networks by analyzing and assessing interaction data. The introduced routing and localization protocols in this dissertation are also extended with a novel three dimensional actor positioning strategy inspired by the molecular geometry. Extensive simulations are conducted in OPNET simulation tool for the performance evaluation of the proposed protocol

Error Minimization in Indoor Wireless Sensor Network Localization Using Genetic Technique

Using the genetic technique, error minimisation in indoor wireless sensor network localisation improves indoor wireless sensor network localisation during this field research. Sensor localisation-based techniques; several wireless device network applications require awareness of each node's physical location. The discovery of the position complete utilising range measurements also as sensor localisation received signal strength in time of arrival and sensor localisation received signal strength in a time difference of arrival and angle of arrival. WSN in positioning algorithms like the angle of arrival between two neighbour nodes. A wireless sensor network using positioning techniques in the area is assumed as localisation. WSNs always operate in an unattended manner, various situations like dynamic situations in the wireless network. It's impossible to exchange sensor manner after deployment. Therefore, a fundamental objective is to optimise the sensor manner lifetime. There has been much specialising in mobile sensor networks, and we have even seen the event of small-profile sensing devices that are ready to control their movement. Although it's been shown that mobility alleviates several issues regarding sensor network coverage and connectivity, many challenges remain node localisation in wireless device network is extremely important for several applications and received signal strength indicator has the capability of sensing, actuating the environmental data the actual-time and favourable information are often collected using the sensor in WSN systems. WSN is often combined with the internet of things to permit the association and extensive access to sensor data, and genetic techniques search the position of the nodes in WSN using all anchor nodes. A proposed algorithm as a genetic technique supported received signal strength, angle of arrival, receptive wireless device and also localisation wireless network. In the study, this paper problem that accuracy is low and error more, but the proposed algorithm overcomes this problem and minimises the error rate. Finally, the simplest possible location satisfies each factor with a minimal error rate and absolute best solution using GA

EFFICIENT CAMERA SELECTION FOR MAXIMIZED TARGET COVERAGE IN UNDERWATER ACOUSTIC SENSOR NETWORKS

In Underwater Acoustic Sensor Networks (UWASNs), cameras have recently been deployed for enhanced monitoring. However, their use has faced several obstacles. Since video capturing and processing consume significant amounts of camera battery power, they are kept in sleep mode and activated only when ultrasonic sensors detect a target. The present study proposes a camera relocation structure in UWASNs to maximize the coverage of detected targets with the least possible vertical camera movement. This approach determines the coverage of each acoustic sensor in advance by getting the most applicable cameras in terms of orientation and frustum of camera in 3-D that are covered by such sensors. Whenever a target is exposed, this information is then used and shared with other sensors that detected the same target. Compared to a flooding-based approach, experiment results indicate that this proposed solution can quickly capture the detected targets with the least camera movement

Efficient Actor Recovery Paradigm for Wireless Sensor and Actor Networks

The actor nodes are the spine of wireless sensor and actor networks (WSANs) that collaborate to perform a specific task in an unverified and uneven environment. Thus, there is a possibility of high failure rate in such unfriendly scenarios due to several factors such as power consumption of devices, electronic circuit failure, software errors in nodes or physical impairment of the actor nodes and inter-actor connectivity problem. Therefore, it is extremely important to discover the failure of a cut-vertex actor and network-disjoint in order to improve the Quality-of-Service (QoS). In this paper, we propose an Efficient Actor Recovery (EAR) paradigm to guarantee the contention-free traffic-forwarding capacity. The EAR paradigm consists of a Node Monitoring and Critical Node Detection (NMCND) algorithm that monitors the activities of the nodes to determine the critical node. In addition, it replaces the critical node with backup node prior to complete node-failure which helps balancing the network performance. The packets are handled using Network Integration and Message Forwarding (NIMF) algorithm that determines the source of forwarding the packets; either from actor or sensor. This decision-making capability of the algorithm controls the packet forwarding rate to maintain the network for a longer time. Furthermore, for handling the proper routing strategy, Priority-Based Routing for Node Failure Avoidance (PRNFA) algorithm is deployed to decide the priority of the packets to be forwarded based on the significance of information available in the packet. To validate the effectiveness of the proposed EAR paradigm, the proposed algorithms were tested using OMNET++ simulation.https://doi.org/10.3390/s1704085

Efficient Actor Recovery Paradigm For Wireless Sensor And Actor Networks

Wireless sensor networks (WSNs) are becoming widely used worldwide. Wireless Sensor and Actor Networks (WSANs) represent a special category of WSNs wherein actors and sensors collaborate to perform specific tasks. WSANs have become one of the most preeminent emerging type of WSNs. Sensors with nodes having limited power resources are responsible for sensing and transmitting events to actor nodes. Actors are high-performance nodes equipped with rich resources that have the ability to collect, process, transmit data and perform various actions. WSANs have a unique architecture that distinguishes them from WSNs. Due to the characteristics of WSANs, numerous challenges arise. Determining the importance of factors usually depends on the application requirements. The actor nodes are the spine of WSANs that collaborate to perform the specific tasks in an unsubstantiated and uneven environment. Thus, there is a possibility of high failure rate in such unfriendly scenarios due to several factors such as power fatigue of devices, electronic circuit failure, software errors in nodes or physical impairment of the actor nodes and inter-actor connectivity problem. It is essential to keep inter-actor connectivity in order to insure network connectivity. Thus, it is extremely important to discover the failure of a cut-vertex actor and network-disjoint in order to improve the Quality-of-Service (QoS). For network recovery process from actor node failure, optimal re-localization and coordination techniques should take place. In this work, we propose an efficient actor recovery (EAR) paradigm to guarantee the contention-free traffic-forwarding capacity. The EAR paradigm consists of Node Monitoring and Critical Node Detection (NMCND) algorithm that monitors the activities of the nodes to determine the critical node. In addition, it replaces the critical node with backup node prior to complete node-failure which helps balances the network performance. The packet is handled using Network Integration and Message Forwarding (NIMF) algorithm that determines the source of forwarding the packets (Either from actor or sensor). This decision-making capability of the algorithm controls the packet forwarding rate to maintain the network for longer time. Furthermore, for handling the proper routing strategy, Priority-Based Routing for Node Failure Avoidance (PRNFA) algorithm is deployed to decide the priority of the packets to be forwarded based on the significance of information available in the packet. To validate the effectiveness of the proposed EAR paradigm, we compare the performance of our proposed work with state-of the art localization algorithms. Our experimental results show superior performance in regards to network life, residual energy, reliability, sensor/ actor recovery time and data recovery

EFFICIENT DYNAMIC ADDRESSING BASED ROUTING FOR UNDERWATER WIRELESS SENSOR NETWORKS

This thesis presents a study about the problem of data gathering in the inhospitable underwater environment. Besides long propagation delays and high error probability, continuous node movement also makes it difficult to manage the routing information during the process of data forwarding. In order to overcome the problem of large propagation delays and unreliable link quality, many algorithms have been proposed and some of them provide good solutions for these issues, yet continuous node movements still need attention. Considering the node mobility as a challenging task, a distributed routing scheme called Hop-by-Hop Dynamic Addressing Based (H2- DAB) routing protocol is proposed where every node in the network will be assigned a routable address quickly and efficiently without any explicit configuration or any dimensional location information. According to our best knowledge, H2-DAB is first addressing based routing approach for underwater wireless sensor networks (UWSNs) and not only has it helped to choose the routing path faster but also efficiently enables a recovery procedure in case of smooth forwarding failure. The proposed scheme provides an option where nodes is able to communicate without any centralized infrastructure, and a mechanism furthermore is available where nodes can come and leave the network without having any serious effect on the rest of the network. Moreover, another serious issue in UWSNs is that acoustic links are subject to high transmission power with high channel impairments that result in higher error rates and temporary path losses, which accordingly restrict the efficiency of these networks. The limited resources have made it difficult to design a protocol which is capable of maximizing the reliability of these networks. For this purpose, a Two-Hop Acknowledgement (2H-ACK) reliability model where two copies of the same data packet are maintained in the network without extra burden on the available resources is proposed. Simulation results show that H2-DAB can easily manage during the quick routing changes where node movements are very frequent yet it requires little or no overhead to efficiently complete its tasks

Questions of development of monitoring system and control of emergency situationsa

Статья посвящена разработке концепции построения автоматизированной системы мониторинга и контроля чрезвычайных ситуаций и определения ее структуры и территориального размещения. Приведены примеры объектов мониторинга и показана актуальность разработки и реализации таких систем. Предложенная концепция подразумевает многоуровневую иерархическую структуру системы мониторинга с открытой архитектурой, на нижнем уровне которой располагаются многофункциональные датчики физических величин устанавливаемых на контролируемых объектах или территориях. Доказано, что в большей степени именно датчики определяют надежность и информативность всей системы мониторинга. Применительно к системе мониторинга селевой опасности, определена номенклатура используемых датчиков. Рассмотрены вопросы повышения информативности и оперативности контроля и оповещения. Показано, что предложенная концепция может быть реализована и штатно функционировать только при наличии современного программно‐аппаратного оснащения. На примере 4‐х уровневой системы мониторинга подробно описаны задачи, решаемые на ее различных уровнях.The article is devoted to the development of the concept of building an auto‐mated system for monitoring and controlling emergencies and determining its structure and location. Examples of monitoring objects are given and the relevance of the development and implementation of such systems is shown. The proposed concept implies a multi‐level hierarchical structure of the monitoring system with an open architecture, at the lower level of which are multifunctional sensors of physical quantities installed on controlled objects or territories. It is proved that, to a greater extent, it is the sensors that determine the reliability and information content of the entire monitoring system. With reference to the mudflow hazard monitoring system, the range of sensors used has been determined. The issues of raising awareness and efficiency of monitoring and warning are considered. It is shown that the proposed concept can be implemented and function properly only with the availability of modern software and hardware. Using the example of a 4‐tier monitoring system, the tasks solved at its various levels are described in detai

EFFICIENT DYNAMIC ADDRESSING BASED ROUTING FOR UNDERWATER WIRELESS SENSOR NETWORKS

This thesis presents a study about the problem of data gathering in the inhospitable underwater environment. Besides long propagation delays and high error probability, continuous node movement also makes it difficult to manage the routing information during the process of data forwarding. In order to overcome the problem of large propagation delays and unreliable link quality, many algorithms have been proposed and some of them provide good solutions for these issues, yet continuous node movements still need attention. Considering the node mobility as a challenging task, a distributed routing scheme called Hop-by-Hop Dynamic Addressing Based (H2- DAB) routing protocol is proposed where every node in the network will be assigned a routable address quickly and efficiently without any explicit configuration or any dimensional location information. According to our best knowledge, H2-DAB is first addressing based routing approach for underwater wireless sensor networks (UWSNs) and not only has it helped to choose the routing path faster but also efficiently enables a recovery procedure in case of smooth forwarding failure. The proposed scheme provides an option where nodes is able to communicate without any centralized infrastructure, and a mechanism furthermore is available where nodes can come and leave the network without having any serious effect on the rest of the network. Moreover, another serious issue in UWSNs is that acoustic links are subject to high transmission power with high channel impairments that result in higher error rates and temporary path losses, which accordingly restrict the efficiency of these networks. The limited resources have made it difficult to design a protocol which is capable of maximizing the reliability of these networks. For this purpose, a Two-Hop Acknowledgement (2H-ACK) reliability model where two copies of the same data packet are maintained in the network without extra burden on the available resources is proposed. Simulation results show that H2-DAB can easily manage during the quick routing changes where node movements are very frequent yet it requires little or no overhead to efficiently complete its tasks

Cooperative Localization in Mobile Underwater Acoustic Sensor Networks

Die großflächige Erkundung und Überwachung von Tiefseegebieten gewinnt mehr und mehr an Bedeutung für Industrie und Wissenschaft. Diese schwer zugänglichen Areale in der Tiefsee können nur mittels Teams unbemannter Tauchbote effizient erkundet werden. Aufgrund der hohen Kosten, war bisher ein Einsatz von mehreren autonomen Unterwasserfahrzeugen (AUV) wirtschaftlich undenkbar, wodurch AUV-Teams nur in Simulationen erforscht werden konnten. In den letzten Jahren konnte jedoch eine Entwicklung hin zu günstigeren und robusteren AUVs beobachtet werden. Somit wird der Einsatz von AUV-Teams in Zukunft zu einer realen Option. Die wachsende Nachfrage nach Technologien zur Unterwasseraufklärung und Überwachung konnte diese Entwicklung noch zusätzlich beschleunigen. Eine der größten technischen Hürden für tief tauchende AUVs ist die Unterwasserlokalisierug. Satelitengestützte Navigation ist in der Tiefe nicht möglich, da Radiowellen bereits nach wenigen Metern im Wasser stark an Intensität verlieren. Daher müssen neue Ansätze für die Unterwasserlokalisierung entwickelt werden die sich auch für Fahrzeugenverbände skalieren lassen. Der Einsatz von AUV-Teams ermöglicht nicht nur völlig neue Möglichkeiten der Kooperation, sondern erlaubt auch jedem einzelnen AUV von den Navigationsdaten der anderen Fahrzeuge im Verband zu profitieren, um die eigene Lokalisierung zu verbessern. In dieser Arbeit wird ein kooperativer Lokalisierungsansatz vorgestellt, welcher auf dem Nachrichtenaustausch durch akustische Ultra-Short Base-Line (USBL) Modems basiert. Ein akustisches Modem ermöglicht die Übertragung von Datenpaketen im Wasser, wärend ein USBL-Sensor die Richtung einer akustischen Quelle bestimmen kann. Durch die Kombination von Modem und Sensor entsteht ein wichtiges Messinstrument für die Unterwasserlokalisierung. Wenn ein Fahrzeug ein Datenpaket mit seiner eignen Position aussendet, können andere Fahrzeuge mit einem USBL-Modem diese Nachricht empfangen. In Verbindung mit der Richtungsmessung zur Quelle, können diese Daten von einem Empfangenden AUV verwendet werden, um seine eigene Positionsschatzung zu verbessern. Diese Arbeit schlägt einen Ansatz zur Fusionierung der empfangenen Nachricht mit der Richtungsmessung vor, welcher auch die jeweiligen Messungenauigkeiten berücksichtigt. Um die Messungenauigkeit des komplexen USBL-Sensors bestimmen zu können, wurde zudem ein detailliertes Sensormodell entwickelt. Zunächst wurden existierende Ansätze zur kooperativen Lokalisierung (CL) untersucht, um daraus eine Liste von erwünschten Eigenschaften für eine CL abzuleiten. Darauf aufbauend wurde der Deep-Sea Network Lokalisation (DNL) Ansatz entwickelt. Bei DNL handelt es sich um eine CL Methode, bei der die Skalierbarkeit sowie die praktische Anwendbarkeit im Fokus stehen. DNL ist als eine Zwischenschicht konzipiert, welche USBL-Modem und Navigationssystem miteinander verbindet. Es werden dabei Messwerte und Kommunikationsdaten des USBL zu einer Standortbestimmung inklusive Richtungsschätzung fusioniert und an das Navigationssystem weiter geleitet, ähnlich einem GPS-Sensor. Die Funktionalität von USBL-Modell und DNL konnten evaluiert werden anhand von Messdaten aus Seeerprobungen in der Ostsee sowie im Mittelatlantik. Die Qualität einer CL hangt häufig von vielen unterschiedlichen Faktoren ab. Die Netzwerktopologie muss genauso berücksichtig werden wie die Lokalisierungsfähigkeiten jedes einzelnen Teilnehmers. Auch das Kommunikationsverhalten der einzelnen Teilnehmer bestimmt, welche Informationen im Netzwerk vorhanden sind und hat somit einen starken Einfluss auf die CL. Um diese Einflussfaktoren zu untersuchen, wurden eine Reihe von Szenarien simuliert, in denen Kommunikationsverhalten und Netzwerktopologie für eine Gruppe von AUVs variiert wurden. In diesen Experimenten wurden die AUVs durch ein Oberflächenfahrzeug unterstützt, welches seine geo-referenzierte Position über DNL an die getauchten Fahrzeuge weiter leitete. Anhand der untersuchten Topologie können die Experimente eingeteilt werden in Single-Hop und Multi-Hop. Single-Hop bedeutet, dass jedes AUV sich in der Sendereichweite des Oberflächenfahrzeugs befindet und dessen Positionsdaten auf direktem Wege erhält. Wie die Ergebnisse der Single-Hop Experimente zeigen, kann der Lokalisierungsfehler der AUVs eingegrenzt werden, wenn man DNL verwendet. Dabei korreliert der Lokalisierungsfehler mit der kombinierten Ungenauigkeit von USBL-Messung und Oberflächenfahrzeugposition. Bei den Multi-Hop Experimenten wurde die Topologie so geändert, dass sich nur eines der AUVs in direkter Sendereichweite des Oberflächenfahrzeugs befindet. Dieses AUV verbessert seine Position mit den empfangen Daten des Oberflächenfahrzeugs und sendet wiederum seine verbesserte Position an die anderen AUVs. Auch hier konnte gezeigt werden, dass sich der Lokalisierungfehler der Gruppe mit DNL einschränken lässt. Ändert man nun das Schema der Kommunikation so, dass alle AUVs zyklisch ihre Position senden, zeigte sich eine Verschlechterung der Lokalisierungsqualität der Gruppe. Dieses unerwartet Ergebnis konnte auf einen Teil des DNL-Algorithmus zurück geführt werden. Da die verwendete USBL-Klasse nur die Richtung eines Signals misst, nicht jedoch die Entfernung zum Sender, wird in der DNL-Schicht eine Entfernungsschatzung vorgenommen. Wenn die Kommunikation nicht streng unidirektional ist, entsteht eine Ruckkopplungsschleife, was zu fehlerhaften Entfernungsschatzungen führt. Im letzten Experiment wird gezeigt wie sich dieses Problem vermeiden lasst, mithilfe einer relativ neue USBL-Klasse, die sowohl Richtung als auch Entfernung zum Sender misst. Die zwei wesentlichen Beiträge dieser Arbeit sind das USBL-Model zum einen und zum Anderen, der neue kooperative Lokalisierungsansatz DNL. Mithilfe des Sensormodels lassen sich nicht nur Messabweichungen einer USBL-Messung bestimmen, es kann auch dazu genutzt werden, einige Fehlereinflüsse zu korrigieren. Mit DNL wurde eine skalierbare CL-Methode entwickelt, die sich gut für den den Einsatz bei mobilen Unterwassersensornetzwerken eignet. Durch das Konzept als Zwischenschicht, lasst sich DNL einfach in bestehende Navigationslösungen integrieren, um die Langzeitstabilität der Navigation für große Verbände von tiefgetauchten Fahrzeugen zu gewährleisten. Sowohl USBL-Model als auch DNL sind dabei so ressourcenschonend, dass sie auf dem Computer eines Standard USBL laufen können, ohne die ursprüngliche Funktionalität einzuschränken, was den praktischen Einsatz zusätzlich vereinfacht