41 research outputs found

    Situation-aware Edge Computing

    Get PDF
    Future wireless networks must cope with an increasing amount of data that needs to be transmitted to or from mobile devices. Furthermore, novel applications, e.g., augmented reality games or autonomous driving, require low latency and high bandwidth at the same time. To address these challenges, the paradigm of edge computing has been proposed. It brings computing closer to the users and takes advantage of the capabilities of telecommunication infrastructures, e.g., cellular base stations or wireless access points, but also of end user devices such as smartphones, wearables, and embedded systems. However, edge computing introduces its own challenges, e.g., economic and business-related questions or device mobility. Being aware of the current situation, i.e., the domain-specific interpretation of environmental information, makes it possible to develop approaches targeting these challenges. In this thesis, the novel concept of situation-aware edge computing is presented. It is divided into three areas: situation-aware infrastructure edge computing, situation-aware device edge computing, and situation-aware embedded edge computing. Therefore, the concepts of situation and situation-awareness are introduced. Furthermore, challenges are identified for each area, and corresponding solutions are presented. In the area of situation-aware infrastructure edge computing, economic and business-related challenges are addressed, since companies offering services and infrastructure edge computing facilities have to find agreements regarding the prices for allowing others to use them. In the area of situation-aware device edge computing, the main challenge is to find suitable nodes that can execute a service and to predict a node’s connection in the near future. Finally, to enable situation-aware embedded edge computing, two novel programming and data analysis approaches are presented that allow programmers to develop situation-aware applications. To show the feasibility, applicability, and importance of situation-aware edge computing, two case studies are presented. The first case study shows how situation-aware edge computing can provide services for emergency response applications, while the second case study presents an approach where network transitions can be implemented in a situation-aware manner

    Unterbrechungstolerante Fahrzeugkommunikation im öffentlichen Personennahverkehr

    Get PDF
    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 ergĂ€nzt und in vielen Anwendungsgebieten sogar vollstĂ€ndig ersetzt. Die Kombination aus unterbrechungstoleranten Netzwerken und lizenzfreien Drahtlostechnologien birgt ein erhebliches Potential zur Reduzierung von Infrastrukturinvestitionen und Betriebskosten, da fĂŒr diese Anwendungen eine dauerhafte Ende-zu-Ende Verbindung nicht mehr erforderlich ist. In dieser Arbeit wird die Machbarkeit eines solchen Systems untersucht und belegt. ZunĂ€chst werden dazu AnwendungsfĂ€lle 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 nĂ€chsten Schritt die besonderen MobilitĂ€tseigenschaften von ÖPNV-Netzen untersucht. Zu diesen Zweck analysieren wir existierende und eigene, neu aufgezeichnete Bewegungsdaten von ÖPNV-Fahrzeugen. Unsere Daten enthalten dabei zusĂ€tzliche Metadaten der Verkehrsbetriebe, die zuvor nicht verfĂŒgbar 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 situationsabhĂ€ngigen Kontaktereignisse vor, sowie den Einfluss der Funkreichweite auf die KontaktkapazitĂ€t. Dann werden die Ergebnisse aller vorhergehenden Schritte verwendet, um ein neues, optimiertes Routingverfahren fĂŒr ÖPNV-Netze vorzuschlagen. In der simulationsbasierten Evaluation belegen wir, dass dieser Router die Leistung bisher bekannter Verfahren ĂŒbertrifft

    Application of Machine Learning Techniques to Delay Tolerant Network Routing

    Get PDF
    This dissertation discusses several machine learning techniques to improve routing in delay tolerant networks (DTNs). These are networks in which there may be long one-way trip times, asymmetric links, high error rates, and deterministic as well as non-deterministic loss of contact between network nodes, such as interplanetary satellite networks, mobile ad hoc networks and wireless sensor networks. This work uses historical network statistics to train a multi-label classifier to predict reliable paths through the network. In addition, a clustering technique is used to predict future mobile node locations. Both of these techniques are used to reduce the consumption of resources such as network bandwidth, memory and data storage that is required by replication routing methods often used in opportunistic DTN environments. Thesis contributions include: an emulation tool chain developed to create a DTN test bed for machine learning, the network and software architecture for a machine learning based routing method, the development and implementation of classification and clustering techniques and performance evaluation in terms of machine learning and routing metrics

    Secure Communication in Disaster Scenarios

    Get PDF
    WĂ€hrend Naturkatastrophen oder terroristischer AnschlĂ€ge ist die bestehende Kommunikationsinfrastruktur hĂ€ufig ĂŒberlastet oder fĂ€llt komplett aus. In diesen Situationen können mobile GerĂ€te mithilfe von drahtloser ad-hoc- und unterbrechungstoleranter Vernetzung miteinander verbunden werden, um ein Notfall-Kommunikationssystem fĂŒr Zivilisten und Rettungsdienste einzurichten. Falls verfĂŒgbar, kann eine Verbindung zu Cloud-Diensten im Internet eine wertvolle Hilfe im Krisen- und Katastrophenmanagement sein. Solche Kommunikationssysteme bergen jedoch ernsthafte Sicherheitsrisiken, da Angreifer versuchen könnten, vertrauliche Daten zu stehlen, gefĂ€lschte Benachrichtigungen von Notfalldiensten einzuspeisen oder Denial-of-Service (DoS) Angriffe durchzufĂŒhren. Diese Dissertation schlĂ€gt neue AnsĂ€tze zur Kommunikation in Notfallnetzen von mobilen GerĂ€ten vor, die von der Kommunikation zwischen MobilfunkgerĂ€ten bis zu Cloud-Diensten auf Servern im Internet reichen. Durch die Nutzung dieser AnsĂ€tze werden die Sicherheit der GerĂ€te-zu-GerĂ€te-Kommunikation, die Sicherheit von Notfall-Apps auf mobilen GerĂ€ten und die Sicherheit von Server-Systemen fĂŒr Cloud-Dienste verbessert

    Connectivity and Data Transmission over Wireless Mobile Systems

    Get PDF
    We live in a world where wireless connectivity is pervasive and becomes ubiquitous. Numerous devices with varying capabilities and multiple interfaces are surrounding us. Most home users use Wi-Fi routers, whereas a large portion of human inhabited land is covered by cellular networks. As the number of these devices, and the services they provide, increase, our needs in bandwidth and interoperability are also augmented. Although deploying additional infrastructure and future protocols may alleviate these problems, efficient use of the available resources is important. We are interested in the problem of identifying the properties of a system able to operate using multiple interfaces, take advantage of user locations, identify the users that should be involved in the routing, and setup a mechanism for information dissemination. The challenges we need to overcome arise from network complexity and heterogeneousness, as well as the fact that they have no single owner or manager. In this thesis I focus on two cases, namely that of utilizing "in-situ" WiFi Access Points to enhance the connections of mobile users, and that of establishing "Virtual Access Points" in locations where there is no fixed roadside equipment available. Both environments have attracted interest for numerous related works. In the first case the main effort is to take advantage of the available bandwidth, while in the second to provide delay tolerant connectivity, possibly in the face of disasters. Our main contribution is to utilize a database to store user locations in the system, and to provide ways to use that information to improve system effectiveness. This feature allows our system to remain effective in specific scenarios and tests, where other approaches fail

    Analyses on tech-enhanced and anonymous Peer Discussion as well as anonymous Control Facilities for tech-enhanced Learning

    Get PDF
    An increasing number of university freshmen has been observable in absolute number as well as percentage of population over the last decade. However, at the same time the drop-out rate has increased significantly. While a drop in attendance could be observed at the same time, statistics show that young professionals consider only roughly thirty percent of their qualification to originate in their university education. Taking this into consideration with the before mentioned, one conclusion could be that students fail to see the importance of fundamental classes and choose to seek knowledge elsewhere, for example in free online courses. However, the so acquired knowledge is a non-attributable qualification. One solution to this problem must be to make on-site activities more attractive. A promising approach for raised attractiveness would be to support students in self-regulated learning processes, making them experience importance and value of own decisions based on realistic self-assessment and self-evaluation. At the same time, strict ex-cathedra teaching should be replaced by interactive forms of education, ideally activating on a meta-cognitive level. Particularly, as many students bring mobile communication devices into classes, this promising approach could be extended by utilising these mobile devices as second screens. That way, enhanced learning experiences can be provided. The basic idea is simple, namely to contribute to psychological concepts with the means of computer science. An example for this idea are audience response systems. There has been numerous research into these and related approaches for university readings, but other forms of education have not been sufficiently considered, for example tutorials. This technological aspect can be combined with recent didactics research and concepts like peer instruction or visible learning. Therefore, this dissertation presents an experimental approach at providing existing IT solutions for on-site tutorials, specifically tools for audience responses, evaluations, learning demand assessments, peer discussion, and virtual interactive whiteboards. These tools are provided under observation of anonymity and cognisant incidental utilisation. They provide insight into students\' motivation to attend classes, their motivation to utilise tools, and into their tool utilisation itself. Experimental findings are combined into an extensible system concept consisting of three major tool classes: anonymous peer discussion means, anonymous control facilities, and learning demand assessment. With the exception of the latter, promising findings in context of tutorials are presented, for example the reduction of audience response systems to an emergency brake, the versatility of (peer) discussion systems, or a demand for retroactive deanonymisation of contributions. The overall positive impact of tool utilisation on motivation to attend and perceived value of tutorials is discussed and supplemented by a positive impact on the final exams\' outcomes.:List of Definitions, Theorems and Proofs List of Figures List of Tables Introduction and Motivation Part I: Propaedeutics 1 Working Theses 1.1 Definitions 1.2 Context of Working Theses and Definitions 2 Existing Concepts 2.1 Psychology 2.1.1 Self-Regulation and self-regulated Learning 2.1.2 Peer Instruction, Peer Discussion 2.1.3 Learning Process Supervision: Learning Demand Assessment 2.1.4 Cognitive Activation 2.1.5 Note on Gamification 2.1.6 Note on Blended Learning 2.2 Computer Science 2.2.1 Learning Platforms 2.2.2 Audience Response Systems (ARS) 2.2.3 Virtual Interactive Whiteboard Systems (V-IWB) 2.2.4 Cognisant Incidential Utilisation (CIU) 2.3 Appraisal 3 Related Work 3.1 Visible Learning 3.2 auditorium 3.3 Auditorium Mobile Classroom Service 3.4 ARSnova and other Audience Response Systems 3.5 Google Classroom 3.6 StackOverflow 3.7 AwwApp Part II: Proceedings 4 Global Picture and Prototype 4.1 Global Picture 4.2 System Architecture 4.2.1 Anonymous Discussion Means 4.2.2 Anonymous Control Facilities 4.3 Implementation 4.3.1 The Prototype 5 Investigated Tools 5.1 Note on Methodology 5.2 Anonymity 5.2.1 Methodology 5.2.2 Visible Learning Effects 5.2.3 Assertion 5.2.4 Experiments 5.2.5 Results 5.2.6 Conclusions 5.3 Learning Demand Assessment 5.3.1 Methodology 5.3.2 Visible Learning Effects 5.3.3 Tool Description 5.3.4 Assertion 5.3.5 Experiments 5.3.6 Results 5.3.7 Conclusions 5.4 Peer Discussion System 5.4.1 Methodology 5.4.2 Visible Learning Effects 5.4.3 Tool Description 5.4.4 Assertion 5.4.5 Experiments 5.4.6 Results 5.4.7 Conclusions 5.5 Virtual Interactive Whiteboard 5.5.1 Methodology 5.5.2 Visible Learning Effects 5.5.3 Tool Description 5.5.4 Assertion 5.5.5 Experiments 5.5.6 Results 5.5.7 Conclusions 5.6 Audience Response System and Emergency Brake 5.6.1 Methodology 5.6.2 Visible Learning Effects 5.6.3 Tool Description 5.6.4 Assertion 5.6.5 Experiments 5.6.6 Results 5.6.7 Conclusions 5.7 Evaluation System 5.7.1 Methodology 5.7.2 Visible Learning Effects 5.7.3 Tool Description 5.7.4 Assertion 5.7.5 Experiments 5.7.6 Results and Conclusion 6 Exam Outcome 7 Utilisation and Motivation 7.1 Prototype Utilisation 7.2 Motivational Aspects Part III: Appraisal 8 Lessons learned 9 Discussion 9.1 Working Theses’ Validity 9.2 Research Community: Impact and Outlook 9.2.1 Significance to Learning Psychology 9.3 Possible Extension of existing Solutions 10 Conclusion 10.1 Summary of scientific Contributions 10.2 Future Work Part IV: Appendix A Experimental Arrangement B Questionnaires B.1 Platform Feedback Sheet B.1.1 Original PFS in 2014 B.1.2 Original PFS in 2015 B.2 Minute Paper B.3 Motivation and Utilisation Questionnaires B.3.1 Motivation 2013 and 2014 B.3.2 Motivation 2015 B.3.3 Utilisation 2014 B.3.4 Utilisation 2015, Rev. I B.3.5 Utilisation 2015, Rev. II C References C.1 Auxiliary Means D Publications D.1 Original Research Contributions D.2 Student Theses E Glossary F Index G Milestones AcknowledgementsÜber die vergangene Dekade ist eine zunehmende Zahl StudienanfĂ€nger beobachtbar, sowohl in der absoluten Anzahl, als auch im Bevölkerungsanteil. DemgegenĂŒber steht aber eine ĂŒberproportional hohe Steigerung der Abbruchquote. WĂ€hrend gleichzeitig die Anwesenheit in universitĂ€ren Lehrveranstaltungen sinkt, zeigen Statistiken, dass nur etwa ein Drittel der Berufseinsteiger die Grundlagen ihrer Qualifikation im Studium sieht. Daraus könnte man ableiten, dass Studierende den Wert und die Bedeutung universitĂ€rer Ausbildung unterschĂ€tzen und stattdessen Wissen in anderen Quellen suchen, beispielsweise unentgeltlichen Online-Angeboten. Das auf diese Art angeeignete Wissen stellt aber eine formell nicht nachweise Qualifikation dar. Ein Weg aus diesem Dilemma muss die Steigerung der AttraktivitĂ€t der universitĂ€ren Lehrveranstaltungen sein. Ein vielversprechender Ansatz ist die UnterstĂŒtzung der Studierenden im selbst-regulierten Lernen, wodurch sie die Wichtigkeit und den Wert eigener Entscheidung(sfindungsprozesse) auf Basis realistischer SelbsteinschĂ€tzung und Selbstevaluation erlernen. Gleichzeitig sollte Frontalunterricht durch interaktive Lehrformen ersetzt werden, idealerweise durch Aktivierung auf meta-kognitiver Ebene. Dies ist vielversprechend insbesondere, weil viele Studierende ihre eigenen mobilen EndgerĂ€te in Lehrveranstaltungen bringen. Diese GerĂ€te können als Second Screen fĂŒr die neuen Lehrkonzepte verwendet werden. Auf diese Art kann dann eine verbesserte Lernerfahrung vermittelt werden. Die Grundidee ist simpel, nĂ€mlich in der Psychologie bewĂ€hrte Didaktik-Konzepte durch die Mittel der Informatik zu unterstĂŒtzen. Ein Beispiel dafĂŒr sind Audience Response Systeme, die hinlĂ€nglich im Rahmen von Vorlesungen untersucht worden sind. Andere Lehrformen wurden dabei jedoch unzureichend berĂŒcksichtigt, beispielsweise Tutorien. Ähnliche Überlegungen gelten natĂŒrlich auch fĂŒr bewĂ€hrte didaktische Konzepte wie Peer Instruction oder Betrachtungen in Form von Visible Learning. Deshalb prĂ€sentiert diese Dissertation einen experimentellen Ansatz, informationstechnische Lösungen fĂŒr vor-Ort-Übungen anzubieten, nĂ€mlich Werkzeuge fĂŒr Audience Response Systeme, Evaluationen, Lernbedarfsermittlung, Peer Discussion, sowie virtuelle interaktive Whiteboards. Die genannten Werkzeuge wurden unter Beachtung von AnonymitĂ€ts- und BeilĂ€ufigkeitsaspekten bereitgestellt. Sie erlauben einen Einblick in die Motivation der Studierenden Tutorien zu besuchen und die Werkzeuge zu nutzen, sowie ihr Nutzungsverhalten selbst. Die experimentellen Ergebnisse werden in ein erweiterbares Systemkonzept kombiniert, das drei Werkzeugklassen unterstĂŒtzt: anonyme Peer Discussion, anonyme Kontrollwerkzeuge und Lernbedarfsermittlung. FĂŒr die ersten beiden Klassen liegen vielversprechende Ergebnisse vor, beispielsweise die notwendige Reduktion des Audience Response Systems auf eine Art Notbremse, die Vielseitigkeit von (Peer-)Discussion-Systemen, oder aber auch der Bedarf fĂŒr eine retroaktive Deanonymisierung von initial anonymen BeitrĂ€gen. Der allgemein positive Einfluss der Werkzeugnutzung auf die Motivation an Tutorien teilzunehmen sowie den wahrgenommenen Wert der Tutorien werden abschließend diskutiert und durch verbesserte Abschlussklausurergebnisse untermauert.:List of Definitions, Theorems and Proofs List of Figures List of Tables Introduction and Motivation Part I: Propaedeutics 1 Working Theses 1.1 Definitions 1.2 Context of Working Theses and Definitions 2 Existing Concepts 2.1 Psychology 2.1.1 Self-Regulation and self-regulated Learning 2.1.2 Peer Instruction, Peer Discussion 2.1.3 Learning Process Supervision: Learning Demand Assessment 2.1.4 Cognitive Activation 2.1.5 Note on Gamification 2.1.6 Note on Blended Learning 2.2 Computer Science 2.2.1 Learning Platforms 2.2.2 Audience Response Systems (ARS) 2.2.3 Virtual Interactive Whiteboard Systems (V-IWB) 2.2.4 Cognisant Incidential Utilisation (CIU) 2.3 Appraisal 3 Related Work 3.1 Visible Learning 3.2 auditorium 3.3 Auditorium Mobile Classroom Service 3.4 ARSnova and other Audience Response Systems 3.5 Google Classroom 3.6 StackOverflow 3.7 AwwApp Part II: Proceedings 4 Global Picture and Prototype 4.1 Global Picture 4.2 System Architecture 4.2.1 Anonymous Discussion Means 4.2.2 Anonymous Control Facilities 4.3 Implementation 4.3.1 The Prototype 5 Investigated Tools 5.1 Note on Methodology 5.2 Anonymity 5.2.1 Methodology 5.2.2 Visible Learning Effects 5.2.3 Assertion 5.2.4 Experiments 5.2.5 Results 5.2.6 Conclusions 5.3 Learning Demand Assessment 5.3.1 Methodology 5.3.2 Visible Learning Effects 5.3.3 Tool Description 5.3.4 Assertion 5.3.5 Experiments 5.3.6 Results 5.3.7 Conclusions 5.4 Peer Discussion System 5.4.1 Methodology 5.4.2 Visible Learning Effects 5.4.3 Tool Description 5.4.4 Assertion 5.4.5 Experiments 5.4.6 Results 5.4.7 Conclusions 5.5 Virtual Interactive Whiteboard 5.5.1 Methodology 5.5.2 Visible Learning Effects 5.5.3 Tool Description 5.5.4 Assertion 5.5.5 Experiments 5.5.6 Results 5.5.7 Conclusions 5.6 Audience Response System and Emergency Brake 5.6.1 Methodology 5.6.2 Visible Learning Effects 5.6.3 Tool Description 5.6.4 Assertion 5.6.5 Experiments 5.6.6 Results 5.6.7 Conclusions 5.7 Evaluation System 5.7.1 Methodology 5.7.2 Visible Learning Effects 5.7.3 Tool Description 5.7.4 Assertion 5.7.5 Experiments 5.7.6 Results and Conclusion 6 Exam Outcome 7 Utilisation and Motivation 7.1 Prototype Utilisation 7.2 Motivational Aspects Part III: Appraisal 8 Lessons learned 9 Discussion 9.1 Working Theses’ Validity 9.2 Research Community: Impact and Outlook 9.2.1 Significance to Learning Psychology 9.3 Possible Extension of existing Solutions 10 Conclusion 10.1 Summary of scientific Contributions 10.2 Future Work Part IV: Appendix A Experimental Arrangement B Questionnaires B.1 Platform Feedback Sheet B.1.1 Original PFS in 2014 B.1.2 Original PFS in 2015 B.2 Minute Paper B.3 Motivation and Utilisation Questionnaires B.3.1 Motivation 2013 and 2014 B.3.2 Motivation 2015 B.3.3 Utilisation 2014 B.3.4 Utilisation 2015, Rev. I B.3.5 Utilisation 2015, Rev. II C References C.1 Auxiliary Means D Publications D.1 Original Research Contributions D.2 Student Theses E Glossary F Index G Milestones Acknowledgement

    Interaktive latenzkritische Anwendungen in mobilen Ad-hoc Netzen

    Get PDF
    In this thesis we discuss the challenges that latency-sensitive interactive applications face in mobile ad-hoc networks. By using multi-player games as an example, we argue that the traditional client-server architecture is unsuitable for this new environment. We consequently create a novel communication architecture as well as quality of service mechanisms that can support the network requirements of such applications in mobile environments. By using a number of distributed zone servers that are selected and managed dynamically by our server selection algorithm, we provide a scalable approach that offers the necessary redundancy. Furthermore, we propose additional quality of service mechanisms to reduce latency and packet loss for interactive applications. We evaluate our approach through network simulation and realistic mobile gaming scenarios. The performance of our evaluation is checked against real-world measurements.In dieser Arbeit werden die Probleme und Herausforderungen von latenz-kritischen interactiven Computeranwendungen in mobilen Ad-hoc Netzen untersucht. Am Beispiel von Mehrbenutzercomputerspielen zeigen wir, dass traditionelle Client-Server Architekturen fĂŒr diese neuen Umgebungen ungeeignet sind. Im Rahmen dieser Arbeit wird daher eine neue Kommunikationsarchitektur sowie verschiedene Mechanismen zur Erhöhung der DienstgĂŒte vorgeschlagen. Mit Hilfe von Zonenserver, die durch den Serverauswahlalgorithmus ausgesucht und verwaltet werden zeigen wir einen Ansatz auf, der sowohl bezĂŒglich der NetzgrĂ¶ĂŸe skalierbar ist als auch die notwendige Redundanz bereitstellt. Wir zeigen die FunktionalitĂ€t und die Leistung unseres Ansatzes mit Hilfe von Netzsimulationen bei denen realistische Szenarien fĂŒr mobiles Spielen simuliert werden. Der hierbei benutze Netzsimulator wurde dafĂŒr auf Basis von eigenen Messungen verbessert und fĂŒr das jeweilige Szenario passend eingestellt

    Wireless Vehicular Communication Based Solution for Road Traffic Efficiency

    Get PDF
    Wireless vehicular communications is a cutting edge set of technologies driven by the vision of providing a suite of original applications, and supported by emerging standards such as IEEE 802.11p. In turn the popularity of these applications is one of the key factors, which will drive the uptake of these vehicular communications technologies and ultimately determine their market success. Applications for vehicular communications can be placed in three main categories - Traffic Safety, Traffic Efficiency and Value-added Services (e.g. Infotainment/Business). Our work focuses on the provision of traffic efficiency services as we believe they offer an immediate benefit and can be adopted quickly by a large number of potential users. Satellite navigation systems provide a ready made deployment platform for these types of services and have already proven popular (14.4 million portable satellite navigation systems sold in Western Europe in 2007). There is also an existing trend toward complementing satellite navigation-related technology with local area wireless communications (by 2013 34% of all portable navigation devices will feature wireless cards 2). Our emphasis is on an infrastructure-based approach as this allows early adopters of wireless enabled satellite navigation devices to receive useful services from day one, regardless of the penetration level of the technology. This thesis describes Smart City, a novel framework, which purposes the use of wireless communication to make city life greener and more efficient. A major contribution to this framework is the proposed intelligent traffic management module. A route management service, which is powered by a best route selection algorithm, is put forward as a prototypical traffic efficiency service for this module. The novel aspect is that the algorithm minimizes journey times and traffic congestion as well as fuel consumption and emissions. Testing has shown how the algorithm provides-shorter journey times, a reduction in fuel consumption and harmful emissions and also results in financial savings. We have proposed and implemented an infrastructure-based communication scheme that enables prioritization of services provided to vehicles
    corecore