Spatial networks with wireless applications

Many networks have nodes located in physical space, with links more common between closely spaced pairs of nodes. For example, the nodes could be wireless devices and links communication channels in a wireless mesh network. We describe recent work involving such networks, considering effects due to the geometry (convex,non-convex, and fractal), node distribution, distance-dependent link probability, mobility, directivity and interference.Comment: Review article- an amended version with a new title from the origina

Opportunistic Networks: Present Scenario- A Mirror Review

Opportunistic Network is form of Delay Tolerant Network (DTN) and regarded as extension to Mobile Ad Hoc Network. OPPNETS are designed to operate especially in those environments which are surrounded by various issues like- High Error Rate, Intermittent Connectivity, High Delay and no defined route between source to destination node. OPPNETS works on the principle of “Store-and-Forward” mechanism as intermediate nodes perform the task of routing from node to node. The intermediate nodes store the messages in their memory until the suitable node is not located in communication range to transfer the message to the destination. OPPNETs suffer from various issues like High Delay, Energy Efficiency of Nodes, Security, High Error Rate and High Latency. The aim of this research paper is to overview various routing protocols available till date for OPPNETs and classify the protocols in terms of their performance. The paper also gives quick review of various Mobility Models and Simulation tools available for OPPNETs simulation

Enabling Auditing and Intrusion Detection of Proprietary Controller Area Networks

The goal of this dissertation is to provide automated methods for security researchers to overcome ‘security through obscurity’ used by manufacturers of proprietary Industrial Control Systems (ICS). `White hat\u27 security analysts waste significant time reverse engineering these systems\u27 opaque network configurations instead of performing meaningful security auditing tasks. Automating the process of documenting proprietary protocol configurations is intended to improve independent security auditing of ICS networks. The major contributions of this dissertation are a novel approach for unsupervised lexical analysis of binary network data flows and analysis of the time series data extracted as a result. We demonstrate the utility of these methods using Controller Area Network (CAN) data sampled from passenger vehicles

Impacts of Mobility Models on RPL-Based Mobile IoT Infrastructures: An Evaluative Comparison and Survey

With the widespread use of IoT applications and the increasing trend in the number of connected smart devices, the concept of routing has become very challenging. In this regard, the IPv6 Routing Protocol for Low-power and Lossy Networks (PRL) was standardized to be adopted in IoT networks. Nevertheless, while mobile IoT domains have gained significant popularity in recent years, since RPL was fundamentally designed for stationary IoT applications, it could not well adjust with the dynamic fluctuations in mobile applications. While there have been a number of studies on tuning RPL for mobile IoT applications, but still there is a high demand for more efforts to reach a standard version of this protocol for such applications. Accordingly, in this survey, we try to conduct a precise and comprehensive experimental study on the impact of various mobility models on the performance of a mobility-aware RPL to help this process. In this regard, a complete and scrutinized survey of the mobility models has been presented to be able to fairly justify and compare the outcome results. A significant set of evaluations has been conducted via precise IoT simulation tools to monitor and compare the performance of the network and its IoT devices in mobile RPL-based IoT applications under the presence of different mobility models from different perspectives including power consumption, reliability, latency, and control packet overhead. This will pave the way for researchers in both academia and industry to be able to compare the impact of various mobility models on the functionality of RPL, and consequently to design and implement application-specific and even a standard version of this protocol, which is capable of being employed in mobile IoT applications

Physics of traffic Gridlock in a city: a study of the spreading of traffic jams on urban street networks

Abstract. Traffic congestion has profound and varied impacts on modern society, yet characterizing on a city scale the transition that gives rise to the congestion remains an elusive task. The challenge lies in understanding the role of the interplay between topology and spatial dynamics in this traffic phenomenon. In this thesis we combine cellular automata modelling with analysis tools from statistical physics to study the emergence of congestions at road (street), grid (neighbourhood) and network (city) levels. At street level, we shown for at least two traffic cellular automata that implementing a simple Monte Carlo exploration of the driving rules reproduces the fundamental diagram of a single road segment. Next, by applying tools of percolation theory, we unveiled the underlying mechanism of jamming process in the Biham-Middleton Levine model, i.e., a paradigmatic model for car traffic, both on square and honeycomb grids, solving a puzzle of more than a decade on the origin of the intermediate states of this model on square grids and pointing out the relevance of both asymmetry and the underlying grid on the model's behaviour. Finally, we used the origin-destination matrices obtained from mobile phone data to simulate car by car the traffic on the detailed road network of five large cities: Rio, Boston, San Francisco bay, Porto and Lisbon. We found at this network level that the characteristic recovery time the system takes to unload is proportional to the fraction of road infrastructure being used and the mean travel time on all trips. In addition, we study the emergence of congestion when the number of cars increases by keeping the trip distributions and street capacities unchanged. Our last findings strongly support the notion that the transitions to urban traffic gridlock resemble the direct percolation universality class and can be approached with the framework of non-equilibrium phase transitions. Our work illustrates the power of a computational description at the level of each car with the solid theoretical framework of statistical physics to analyze the origins and behaviour or vehicular traffic congestion.La congestión vehícular tiene un impacto profundo y diverso en la sociedad actual. Sin embargo, caracterizar a nivel de ciudad la transición que da lugar a la congestión ha sido una tarea inalcanzable. El problema se centra en la dificultad para entender la interacción que existe entre la topología de la red y la dinámica espacial del flujo vehícular. En esta tesis se combina el modelamiento por autómatas celulares con herramientas de la física estadística para estudiar la formación de la congestión a escala de calle, de malla regular y de red real de calles. A nivel de calle, mostramos que para al menos dos modelos de autómata celular, una exploración por Monte Carlo de las reglas de manejo permite reproducir el diagrama fundamental de una calle. A nivel de mallas regulares, el modelo Biham-Middleton-Levine (BML) es el paradigma de los estudios de tráfico vehícular. Aplicando las herramientas de la Teor\'ia de Percolación, logramos desentrañar los mecanismos de formación de atascos en este modelo, ya sea sobre mallas cuadradas o tipo panal. Logramos entonces resolver el misterio del origen los llamados estados intermedios en el BML en mallas cuadradas. Finalmente, usamos las matrices origen destino obtenidas a partir de datos de telefonía móvil para simular el tráfico vehícular de cinco ciudades alrededor del mundo: Río de Janeiro, Boston, la bahía de San Francisco, Porto y Lisboa. A este nivel de red de ciudad, encontramos que el tiempo de recuperación característico de cada ciudad es proporcional a la fracción de infraestructura utilizada y el tiempo promedio de viaje. Adicionalmente, incrementando la demanda, estudiamos el colapso vehícular en redes de ciudad bajo el marco de transiciones de fase fuera del equilibrio. Nuestros resultados muestran características similares a las observados en los modelos dentro de la clase de universalidad de percolación dirigida (DP). Nuestro trabajo ilustra cómo una descripción computacional a nivel de vehículo junto con las herramientas de la física estadística permite analizar y comprender los orígenes y el comportamiento de la congestión vehícular.Doctorad

Information dissemination in mobile networks

This thesis proposes some solutions to relieve, using Wi-Fi wireless networks, the data consumption of cellular networks using cooperation between nodes, studies how to make a good deployment of access points to optimize the dissemination of contents, analyzes some mechanisms to reduce the nodes' power consumption during data dissemination in opportunistic networks, as well as explores some of the risks that arise in these networks. Among the applications that are being discussed for data off-loading from cellular networks, we can find Information Dissemination in Mobile Networks. In particular, for this thesis, the Mobile Networks will consist of Vehicular Ad-hoc Networks and Pedestrian Ad-Hoc Networks. In both scenarios we will find applications with the purpose of vehicle-to-vehicle or pedestrian-to-pedestrian Information dissemination, as well as vehicle-to-infrastructure or pedestrian-to-infrastructure Information dissemination. We will see how both scenarios (vehicular and pedestrian) share many characteristics, while on the other hand some differences make them unique, and therefore requiring of specific solutions. For example, large car batteries relegate power saving techniques to a second place, while power-saving techniques and its effects to network performance is a really relevant issue in Pedestrian networks. While Cellular Networks offer geographically full-coverage, in opportunistic Wi-Fi wireless solutions the short-range non-fullcoverage paradigm as well as the high mobility of the nodes requires different network abstractions like opportunistic networking, Disruptive/Delay Tolerant Networks (DTN) and Network Coding to analyze them. And as a particular application of Dissemination in Mobile Networks, we will study the malware spread in Mobile Networks. Even though it relies on similar spreading mechanisms, we will see how it entails a different perspective on Dissemination

Applications

Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

Unterbrechungstolerante Fahrzeugkommunikation im öffentlichen Personennahverkehr

Communication systems play an important role in the efficient operation of public transport networks. Recently, traditional voice-centric real-time communication is complemented and often replaced by data-centric asynchronous machine-to-machine communication. Disruption tolerant networking in combination with license-exempt high bandwidth technologies have the potential to reduce infrastructure investments and operating costs for such applications, because a continuous end-to-end connectivity is no longer required. In this thesis the feasibility of such a system is investigated and confirmed. First, realistic use-cases are introduced and the requirements to the communication system are analyzed. Then the channel characteristics of several WLAN-based technologies are experimentally evaluated in real public transport scenarios. Since the results are promising, the next step is gaining a deeper understanding of the special mobility properties in public transport networks. Therefore, we analyze existing traces as well as our own newly acquired trace. Our trace features additional operator meta-data that is not available for existing traces, and we report on unexpected properties that have not been quantified before. Then the trace is combined with the experimentally obtained channel parameters in order to analyze the characteristics of inter-vehicle contacts. We present the statistical distribution of situation-specific contact events and the impact of radio range on contact capacity. Then results of all steps above are used to propose a routing scheme that is optimized for public transport networks. In the final simulation-based evaluation we show that this router outperforms previously proposed algorithms.Kommunikationssysteme leisten einen wichtigen Beitrag zum effizienten Betrieb des öffentlichen Personennahverkehrs. Seit einigen Jahren wird dabei der Sprechfunk zunehmend durch asynchronen M2M-Datenfunk ergänzt und in vielen Anwendungsgebieten sogar vollständig ersetzt. Die Kombination aus unterbrechungstoleranten Netzwerken und lizenzfreien Drahtlostechnologien birgt ein erhebliches Potential zur Reduzierung von Infrastrukturinvestitionen und Betriebskosten, da für diese Anwendungen eine dauerhafte Ende-zu-Ende Verbindung nicht mehr erforderlich ist. In dieser Arbeit wird die Machbarkeit eines solchen Systems untersucht und belegt. Zunächst werden dazu Anwendungsfälle vorgestellt und deren Anforderungen an das Kommunikationssystem analysiert. Dann werden die Kanalcharakteristika mehrerer WLAN-Technologien im realen ÖPNV-Umfeld experimentell ermittelt und bewertet. Auf Grundlage der erfolgversprechenden Ergebnisse werden im nächsten Schritt die besonderen Mobilitätseigenschaften von ÖPNV-Netzen untersucht. Zu diesen Zweck analysieren wir existierende und eigene, neu aufgezeichnete Bewegungsdaten von ÖPNV-Fahrzeugen. Unsere Daten enthalten dabei zusätzliche Metadaten der Verkehrsbetriebe, die zuvor nicht verfügbar waren, so dass wir unerwartete Effekte beschreiben und erstmals quantifizieren können. Anschließend werden die Bewegungsdaten mit den zuvor experimentell erfassten Kanaleigenschaften kombiniert, um so die Kommunikationskontakte zwischen den Fahrzeugen genauer zu betrachten. Wir stellen die statistische Verteilung der situationsabhängigen Kontaktereignisse vor, sowie den Einfluss der Funkreichweite auf die Kontaktkapazität. Dann werden die Ergebnisse aller vorhergehenden Schritte verwendet, um ein neues, optimiertes Routingverfahren für ÖPNV-Netze vorzuschlagen. In der simulationsbasierten Evaluation belegen wir, dass dieser Router die Leistung bisher bekannter Verfahren übertrifft