Information collection algorithm for vehicular ad-hoc networks (application domain: Urban Traffic Wireless Vehicular Ad-Hoc Networks (VANETs))

Vehicle to vehicle communication (V2VC) is one of the modern approaches for exchanging and generating traffic information with (yet to be realized) potential to improve road safety, driving comfort and traffic control. In this research, we present a novel algorithm which is based on V2V communication, uses in-vehicle sensor information and in collaboration with the other vehicles' sensor information can detect road conditions and determine the geographical area where this road condition exists – e.g. geographical area where there is traffic density, unusual traffic behaviour, a range of weather conditions (raining), etc. The algorithms' built-in automatic geographical restriction of the data collection, aggregation and dissemination mechanisms allows warning messages to be received by any car, not necessarily sharing the identified road condition, which may then be used to identify the optimum route taken by the vehicle e.g. avoid bottlenecks or dangerous areas including accidents or congestions on their current routes. This research covers the middle ground between MANET [1] and collaborative data generation based on knowledge granularity (aggregation). It investigates the possibility of designing, implementing and modelling of the functionality of an algorithm (as part of the design of an intelligent node in an Intelligent Transportation System - ITS) that ensures active participation in the formation, routing and general network support of MANETs and also helps in-car traffic information and real-time control generation and distribution. The work is natural extension of the efforts of several large EU projects like DRIVE [2], GST [3] and SAFESPOT [4]

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Modeling and Analysis of Location Service Management in Vehicular Ad Hoc Networks

Recent technological advances in wireless communication and the pervasiveness of various wireless communication devices have offered novel and promising solutions to enable vehicles to communicate with each other, establishing a decentralized communication system. An emerging solution in this area is the Vehicular Ad Hoc Networks (VANETs), in which vehicles cooperate in receiving and delivering messages to each other. VANETs can provide a viable alternative in situations where existing infrastructure communication systems become overloaded, fail (due for instance to natural disaster), or inconvenient to use. Nevertheless, the success of VANETs revolves around a number of key elements, an important one of which is the way messages are routed between sources and destinations. Without an effective message routing strategy VANETs' success will continue to be limited. In order for messages to be routed to a destination effectively, the location of the destination must be determined. Since vehicles move in relatively fast and in a random manner, determining the location (hence the optimal message routing path) of (to) the destination vehicle constitutes a major challenge. Recent approaches for tackling this challenge have resulted in a number of Location Service Management Protocols. Though these protocols have demonstrated good potential, they still suffer from a number of impediments, including, signaling volume (particularly in large scale VANETs), inability to deal with network voids and inability to leverage locality for communication between the network nodes. In this thesis, a Region-based Location Service Management Protocol (RLSMP) is proposed. The protocol is a self-organizing framework that uses message aggregation and geographical clustering to minimize the volume of signalling overhead. To the best of my knowledge, RLSMP is the first protocol that uses message aggregation in both updating and querying, and as such it promises scalability, locality awareness, and fault tolerance. Location service management further addresses the issue of routing location updating and querying messages. Updating and querying messages should be exchanged between the network nodes and the location servers with minimum delay. This necessity introduces a persuasive need to support Quality of Service (QoS) routing in VANETs. To mitigate the QoS routing challenge in VANETs, the thesis proposes an Adaptive Message Routing (AMR) protocol that utilizes the network's local topology information in order to find the route with minimum end-to-end delay, while maintaining the required thresholds for connectivity probability and hop count. The QoS routing problem is formulated as a constrained optimization problem for which a genetic algorithm is proposed. The thesis presents experiments to validate the proposed protocol and test its performance under various network conditions

Contributions to Vehicular Communications Systems and Schemes

La dernière décennie a marqué une grande hausse des applications véhiculaires comme une nouvelle source de revenus et un facteur de distinction dans l'industrie des véhicules. Ces applications véhiculaires sont classées en deux groupes : les applications de sécurité et les applications d'info divertissement. Le premier groupe inclue le changement intelligent de voie, l'avertissement de dangers de routes et la prévention coopérative de collision qui comprend la vidéo sur demande (VoD), la diffusion en direct, la diffusion de météo et de nouvelles et les jeux interactifs. Cependant, Il est à noter que d'une part, les applications véhiculaires d'info divertissement nécessitent une bande passante élevée et une latence relativement faible ; D'autre part, les applications de sécurité requièrent exigent un délai de bout en bout très bas et un canal de communication fiable pour la livraison des messages d'urgence. Pour satisfaire le besoin en applications efficaces, les fabricants de véhicules ainsi que la communauté académique ont introduit plusieurs applications à l’intérieur de véhicule et entre véhicule et véhicule (V2V). Sauf que, l'infrastructure du réseau sans fil n'a pas été conçue pour gérer les applications de véhicules, en raison de la haute mobilité des véhicules, de l'imprévisibilité du comportement des conducteurs et des modèles de trafic dynamiques. La relève est l'un des principaux défis des réseaux de véhicules, car la haute mobilité exige au réseau sans fil de faire la relève en un très court temps. De plus, l'imprévisibilité du comportement du conducteur cause l'échec des protocoles proactifs traditionnels de relève, car la prédiction du prochain routeur peut changer en fonction de la décision du conducteur. Aussi, le réseau de véhicules peut subir une mauvaise qualité de service dans les régions de relève en raison d'obstacles naturels, de véhicules de grande taille ou de mauvaises conditions météorologiques. Cette thèse se concentre sur la relève dans l'environnement des véhicules et son effet sur les applications véhiculaires. Nous proposons des solutions pratiques pour les réseaux actuellement déployés, principalement les réseaux LTE, l'infrastructure véhicule à véhicule (V2V) ainsi que les outils efficaces d’émulateurs de relèves dans les réseaux véhiculaires.----------ABSTRACT: The last decade marked the rise of vehicular applications as a new source of revenue and a key differentiator in the vehicular industry. Vehicular Applications are classified into safety and infotainment applications. The former include smart lane change, road hazard warning, and cooperative collision avoidance; however, the latter include Video on Demand (VoD), live streaming, weather and news broadcast, and interactive games. On one hand, infotainment vehicular applications require high bandwidth and relatively low latency; on the other hand, safety applications requires a very low end to end delay and a reliable communication channel to deliver emergency messages. To satisfy the thirst for practical applications, vehicle manufacturers along with research institutes introduced several in-vehicle and Vehicle to Vehicle (V2V) applications. However, the wireless network infrastructure was not designed to handle vehicular applications, due to the high mobility of vehicles, unpredictability of drivers’ behavior, and dynamic traffic patterns. Handoff is one of the main challenges of vehicular networks since the high mobility puts pressure on the wireless network to finish the handoff within a short period. Moreover, the unpredictability of driver behavior causes the traditional proactive handoff protocols to fail, since the prediction of the next router may change based on the driver’s decision. Moreover, the vehicular network may suffer from bad Quality of Service (QoS) in the regions of handoff due to natural obstacles, large vehicles, or weather conditions. This thesis focuses on the handoff on the vehicular environment and its effect on the vehicular applications. We consider practical solutions for the currently deployed networks mainly Long Term Evolution (LTE) networks, the Vehicle to Vehicle (V2V) infrastructure, and the tools that can be used effectively to emulate handoff on the vehicular networks

Rohc-Mpls Tunnel Architecture For Wireless Mesh

Natural or human-made disasters are sudden events that can cause significant damage, especially to the network communication infrastructure. In these events, a rapid deployment of network communication systems is required in order to relay or receive the communication among the people in the disaster areas to conduct relief and rescue efforts. Wireless mesh networks have emerged and has been recognised for its potential for rapid deployment and last mile coverage of network infrastructure, which is highly suitable for emergency response management. While wireless mesh networks have beneficial attributes, it also introduces some crucial problems. During data transmission, the path recovery time is significantly higher resulting in the loss of data if node and link failures occur

A Comprehensive Survey on Routing and Security in Mobile Wireless Sensor Networks

With the continuous advances in mobile wirelesssensor networks (MWSNs), the research community hasresponded to the challenges and constraints in the design of thesenetworks by proposing efficient routing protocols that focus onparticular performance metrics such as residual energy utilization,mobility, topology, scalability, localization, data collection routing,Quality of Service (QoS), etc. In addition, the introduction ofmobility in WSN has brought new challenges for the routing,stability, security, and reliability of WSNs. Therefore, in thisarticle, we present a comprehensive and meticulous investigationin the routing protocols and security challenges in the theory ofMWSNs which was developed in recent years

Avaliação por simulação da comunicação entre veículos

Mestrado em Engenharia Electrónica e TelecomunicaçõesNuma rede veicular, a densidade de veículos (com o tipo de comunicação IEEE 802.11p) que formam a rede veicular será um dos pontos chave para o sucesso da comunicação entre os mesmos. Nos cenários de auto-estrada, o caso mais estudado ao longo desta dissertação, existe uma grande probabilidade de a rede veicular se encontrar desligada, ou seja, de não existir um caminho entre veículos sempre ao alcance, o que diminuirá a viabilidade e qualidade das comunicações. Para melhorar a comunicação nestes cenários podem ser integradas na rede estações fixas, conhecidas por Road Side Units (RSUs). A utilização de RSUs permite melhorar as comunicações entre veículos conseguindo reduzir, essencialmente, o atraso na entrega das mensagens, pois pretende-se que essa inserção diminua a probabilidade de partição da rede entre os veículos. Nesta Dissertação são idealizados e implementados no simulador ns-3 cenários diferentes, com diferentes densidades de veículos, que permitem avaliar a influência das RSUs nas comunicações veiculares. Pelos resultados apresentados, verifica-se que existe uma melhoria significativa nas comunicações quando as RSUs estão ligadas através de rede fixa, por exemplo a Ethernet. Com RSUs ligadas por redes sem fios, existe uma melhoria significativa das comunicações, mas esta melhoria é inferior à existente em cenários de RSUs ligadas por uma rede com fios. Quando as RSUs se encontram desligadas, verifica-se que não existe grande melhoria e as comunicações ficam mais instáveis. Cada RSU tem um custo bastante elevado. Sendo assim, um dos desafios desta Dissertação é o de conseguir melhorar, de facto, a comunicação entre os veículos, mas reduzindo ao máximo o número de RSUs necessárias no cenário, garantindo sempre essa melhoria nas comunicações. Ao longo do trabalho desenvolvido verificou-se que o espaçamento ideal entre as RSUs, para os testes realizados, é de 1800m.In a Vehicular network, the density of vehicles (enabled with the standard IEEE 802.11p) that form the network is one of the keys to the success of intervehicular communication. In highway scenarios, which will be the focus of this Master dissertation, the probability of having a disconnected vehicular network can be very high — in other words, the probability of having no paths within reach between vehicles can be very high, which hinders communication reliability. To improve the communication in these scenarios we can use infrastructure known as Road Side Units (RSUs). When we use RSUs as fixed points for communication in highways, we expect an enhancement on the network performance with an improvement on the propagation delay of messages between the disconnected vehicles. In this Dissertation, we idealized and implemented different scenarios in a network simulator (ns-3), with different densities of vehicles used to evaluate the influence of RSUs in inter-vehicular communication. The results show that, with RSUs interconnected by Ethernet, we have a significant improvement on the network performance. With RSUs interconnected by Wi-Fi, we also see improvements on the network performance, albeit less significant than those of the scenarios with RSUs connected by a wired network. When the RSUs are disconnected, we observe that there is no improvement and communications become unstable. Each RSU has a high cost; therefore, in this Dissertation, we need to minimize the distribution of RSUs while still providing a significant improvement on communications. In this work we have shown that the ideal spacing between the RSUs, in our tests, was of approximately 1800m