Building Realistic Mobility Models for Mobile Ad Hoc Networks

A mobile ad hoc network (MANET) is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP) model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR), destination-sequenced distance-vector routing (DSDV), and ad hoc n-demand distance vector routing (AODV). The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To conclude, it is possible to develop a range of techniques for modelling scenarios applicable to MANETs, and these simulation models could be utilised for the evaluation of routing protocols

Social internet of vehicles for smart cities

Open Access journa

Design and evaluation of safety-critical applications based on inter-vehicle communication

Inter-vehicle communication has a potential to improve road traffic safety and efficiency. Technical feasibility of communication between vehicles has been extensively studied, but due to the scarcity of application-level research, communication\u27s impact on the road traffic is still unclear. This thesis addresses this uncertainty by designing and evaluating two fail-safe applications, namely, Rear-End Collision Avoidance and Virtual Traffic Lights

Recent Developments on Mobile Ad-Hoc Networks and Vehicular Ad-Hoc Networks

This book presents collective works published in the recent Special Issue (SI) entitled "Recent Developments on Mobile Ad-Hoc Networks and Vehicular Ad-Hoc Networks”. These works expose the readership to the latest solutions and techniques for MANETs and VANETs. They cover interesting topics such as power-aware optimization solutions for MANETs, data dissemination in VANETs, adaptive multi-hop broadcast schemes for VANETs, multi-metric routing protocols for VANETs, and incentive mechanisms to encourage the distribution of information in VANETs. The book demonstrates pioneering work in these fields, investigates novel solutions and methods, and discusses future trends in these field

Zuverlässigkeitsbewertung von Fahrzeug-zu-Fahrzeug Kommunikation

V2V communication enables a plethora of cooperative applications aimed at reducing road hazard situations as well as enhancing traffic efficiency and individual driving comfort, expanding therewith the boundaries of Advanced Driver Assistance Systems (ADAS). These applications will be supported by IEEE 802.11p, a standard operating in the 5.9GHz frequency band and adapted for the highly dynamic vehicular environment. The focus of this work is V2V safety applications, which have already gained a major attention from the industry, academia, as well as standardization bodies. Being a subject of wireless communication the performance of V2V applications directly depends on the communication link quality and the packet distribution pattern. Therefore, the main purpose of this thesis is to develop an effective communication link reliability assessment method and analyze to what extent V2V communication is feasible to satisfy the reliability requirements of safety applications. Furthermore, we investigate the effectiveness of the proposed assessment method when applied for real-time communication link reliability prediction. In particular, in this work we establish the link between classical network performance metrics and specific application reliability requirements and derive a set of advanced assessment metrics. Afterwards, we investigate through these metrics how different environmental factors affect application reliability based on the measurement data, which was obtained in elaborated real-world measurement campaigns and in different non-line-of-sight scenarios. Using the suggested metrics further in this work we additionally analyze the achievable application reliability of the V2V safety applications in congested network scenarios through the simulation study. Based on these results we also define the most favorable combinations of the network parameters to support reliable operation of these applications. Finally, in this thesis we examine to what extent the suggested metrics are suitable for applications while operating in real time. We develop and implement two frameworks for prediction of the communication link reliability, based on the data that was obtained over the 4.5 months of the simTD project field trials. Furthermore, we apply both frameworks to other measurement data, which was obtained outside the simTD project and assess the effectiveness of both frameworks under independent realistic conditions.Car2Car-Kommunikation ermöglicht eine Vielzahl von kooperativen Anwendungen, welche auf die Unfallverminderung, Verbesserung der Verkehrseffizienz sowie den individuellen Fahrkomfort abzielen und damit die Grenzen von aktiven Fahrerassistenzsystemen erweitern. Im Fokus dieser Dissertation stehen Car2Car-Sicherheitsanwendungen, denen heutzutage bereits große Aufmerksamkeit von Seiten der Industrie, Forschung und diversen Normierungsgremien geschenkt wird. Da alle diese Anwendungen auf drahtloser Kommunikation basieren, ist ihre Leistungsfähigkeit direkt von der Qualität der Kommunikationsverbindung sowie dem Paketverteilungsmuster abhängig. Daher liegt der Hauptfokus dieser Arbeit in der Entwicklung effektiver Methoden zur Bewertung der Kommunikationszuverlässigkeit und der Analyse, inwieweit Car2Car-Kommunikation im Allgemeinen die Anforderungen von Sicherheitsanwendungen erfüllt. Darüber hinaus untersucht diese Doktorarbeit die Effektivität der hier vorgeschlagenen Bewertungsmethoden in Bezug auf die Vorhersage der Kommunikationszuverlässigkeit in Echtzeit-Szenarien. Im Speziellen verbindet diese Arbeit die Welt der klassischen Netzwerkperformance-Metriken mit Car2Car-Anwendungsspezifischen Zuverlässigkeitsanforderungen und stellt als Ergebnis eine Reihe effektiver Bewertungskennzahlen vor. Mithilfe der vorgeschlagenen Metriken wird des Weiteren untersucht, inwieweit verschiedene Umweltfaktoren die Anwendungszuverlässigkeit beeinflussen können. Diese Untersuchung basiert auf Messdaten, die in ausführlichen Feldversuchen in verschiedenen Non-Line-of-Sight-Szenarien gewonnen wurden. Im nächsten Schritt analysiert diese Doktorarbeit die erreichbare Zuverlässigkeit der Car2Car-Sicherheitsanwendungen in Netzwerküberlastungsszenarien anhand einer Simulationsstudie. Als Ergebnis werden die spezifischen Kombinationen der verschiedenen Netzwerkparameter definiert, die einen zuverlässigen Betrieb der Car2Car-Sicherheitsanwendungen gewährleisten können. Zum Abschluss untersucht diese Dissertation, inwieweit die vorgeschlagenen Metriken für die im Echtzeit-Modus funktionierenden Anwendungen geeignet sind. Darüber hinaus werden zwei Frameworks entwickelt und implementiert, welche die Zuverlässigkeit der Kommunikationsverbindung prädizieren. Dies geschieht basierend auf Daten, die während der 4.5 Monate dauernden Feldversuche im Rahmen des simTD Projektes gewonnen wurden. Beide Frameworks werden am Ende anhand unabhängiger Messdaten auf ihre Funktionalität unter realistischen Bedingungen getestet

Modern Random Access for Satellite Communications

The present PhD dissertation focuses on modern random access (RA) techniques. In the first part an slot- and frame-asynchronous RA scheme adopting replicas, successive interference cancellation and combining techniques is presented and its performance analysed. The comparison of both slot-synchronous and asynchronous RA at higher layer, follows. Next, the optimization procedure, for slot-synchronous RA with irregular repetitions, is extended to the Rayleigh block fading channel. Finally, random access with multiple receivers is considered.Comment: PhD Thesis, 196 page

Indoor Positioning and Navigation

In recent years, rapid development in robotics, mobile, and communication technologies has encouraged many studies in the field of localization and navigation in indoor environments. An accurate localization system that can operate in an indoor environment has considerable practical value, because it can be built into autonomous mobile systems or a personal navigation system on a smartphone for guiding people through airports, shopping malls, museums and other public institutions, etc. Such a system would be particularly useful for blind people. Modern smartphones are equipped with numerous sensors (such as inertial sensors, cameras, and barometers) and communication modules (such as WiFi, Bluetooth, NFC, LTE/5G, and UWB capabilities), which enable the implementation of various localization algorithms, namely, visual localization, inertial navigation system, and radio localization. For the mapping of indoor environments and localization of autonomous mobile sysems, LIDAR sensors are also frequently used in addition to smartphone sensors. Visual localization and inertial navigation systems are sensitive to external disturbances; therefore, sensor fusion approaches can be used for the implementation of robust localization algorithms. These have to be optimized in order to be computationally efficient, which is essential for real-time processing and low energy consumption on a smartphone or robot

Evaluierung der Energie-Effizienz von Sicherheitsmechanismen in drahtlosen Sensornetzen

Im Rahmen dieser Arbeit wurde der Einfluss verschiedener Faktoren auf den Energiebedarf von Sicherheitsmechanismen in drahtlosen Sensornetzen evaluiert. Im Mittelpunkt der Untersuchungen stand insbesondere der Einfluss des Medienzugriffsverfahrens auf den Energiebedarf von (hardwarebasierten) Sicherheitsmechanismen. Als Evaluierungswerkzeuge kam dabei neben dem Testbed SANDBed auch der Simulator AVRORA+ zum Einsatz, dessen Energiemodell im Rahmen dieser Dissertation entstand