On the Necessity for High-availability Data Center Backends in a Distributed Wireless System

When business processes depend on the processing capabilities within a data center, the typical system architecture use a high-availability setup to maintain a high level of service. Faced with a specific machine-to-machine system consisting of many endpoints that collect and forward data to the data center we argue that the dependability of the overall system does not necessitate a high level of service for the data center components. Taking an existing discrete event simulation model of a distributed technical system we investigate and discuss the effects of prolonged outages of the data center on the major business processes of the system

Platforms and Protocols for the Internet of Things

Building a general architecture for the Internet of Things (IoT) is a very complex task, exacerbated by the extremely large variety of devices, link layer technologies, and services that may be involved in such a system. In this paper, we identify the main blocks of a generic IoT architecture, describing their features and requirements, and analyze the most common approaches proposed in the literature for each block. In particular, we compare three of the most important communication technologies for IoT purposes, i.e., REST, MQTT, and AMQP, and we also analyze three IoT platforms: openHAB, Sentilo, and Parse. The analysis will prove the importance of adopting an integrated approach that jointly addresses several issues and is able to flexibly accommodate the requirements of the various elements of the system. We also discuss a use case which illustrates the design challenges and the choices to make when selecting which protocols and technologies to use

Deep Dive into the IoT Backend Ecosystem

Internet of Things (IoT) devices are becoming increasingly ubiquitous, e.g., at home, in enterprise environments, and in production lines. To support the advanced functionalities of IoT devices, IoT vendors as well as service and cloud companies operate IoT backends -- the focus of this paper. We propose a methodology to identify and locate them by (a) compiling a list of domains used exclusively by major IoT backend providers and (b) then identifying their server IP addresses. We rely on multiple sources, including IoT backend provider documentation, passive DNS data, and active scanning. For analyzing IoT traffic patterns, we rely on passive network flows from a major European ISP. Our analysis focuses on the top IoT backends and unveils diverse operational strategies -- from operating their own infrastructure to utilizing the public cloud. We find that the majority of the top IoT backend providers are located in multiple locations and countries. Still, a handful are located only in one country, which could raise regulatory scrutiny as the client IoT devices are located in other regions. Indeed, our analysis shows that up to 35% of IoT traffic is exchanged with IoT backend servers located in other continents. We also find that at least six of the top IoT backends rely on other IoT backend providers. We also evaluate if cascading effects among the IoT backend providers are possible in the event of an outage, a misconfiguration, or an attack

Secure Communication in Disaster Scenarios

Während Naturkatastrophen oder terroristischer Anschläge ist die bestehende Kommunikationsinfrastruktur häufig überlastet oder fällt komplett aus. In diesen Situationen können mobile Geräte mithilfe von drahtloser ad-hoc- und unterbrechungstoleranter Vernetzung miteinander verbunden werden, um ein Notfall-Kommunikationssystem für Zivilisten und Rettungsdienste einzurichten. Falls verfügbar, 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, gefälschte Benachrichtigungen von Notfalldiensten einzuspeisen oder Denial-of-Service (DoS) Angriffe durchzuführen. Diese Dissertation schlägt neue Ansätze zur Kommunikation in Notfallnetzen von mobilen Geräten vor, die von der Kommunikation zwischen Mobilfunkgeräten bis zu Cloud-Diensten auf Servern im Internet reichen. Durch die Nutzung dieser Ansätze werden die Sicherheit der Geräte-zu-Geräte-Kommunikation, die Sicherheit von Notfall-Apps auf mobilen Geräten und die Sicherheit von Server-Systemen für Cloud-Dienste verbessert

Energy efficient resource sharing for networked homes

Diese Arbeit beschäftigt sich mit Energieeffizienz für Heimnetzwerke. Sie zeigt inwiefern Stromsparen mittels Ressourcen- und Aufgaben-Sharing durch Kooperation möglich ist. Der globale Stromverbrauch eines Netzwerkes von Heimen, und auch der lokale Stromverbrauch eines einzelnen Heimes, können durch Lastkonzentration reduziert werden. Die Energieeffizienz des verteilten Falls, in welchem Aufgaben unter den Heimen verteilt werden, wird mit der Energieeffizienz des lokalen Falls ohne Verteilung für die gleiche Last verglichen. Eine Architektur, basierend auf Konzepten des Ressourcen-Sharings, der Virtualisierung und virtuellen Heimumgebungen, wird vorgestellt. Für diese Architektur werden Applikationen mit typischen Ressourcen-Anforderungen erforscht um aufzuzeigen unter welchen Umständen Strom gespart werden kann. Analytische Modelle und Simulationsmodelle sind entwickelt worden um den Vorteil des verteilten Falls unter verschiedenen Aspekten darzustellen

Distributed GIS for automated natural hazard zonation mapping internet-SMS warning towards sustainable society

Today, open systems are needed for real time analysis and warnings on geo-hazards and over time can be achieved using Open Source Geographical Information System (GIS)-based platform such as GeoNode which is being contributed to by developers around the world. To develop on an open source platform is a very vital component for better disaster information management as far as spatial data infrastructures are concerned and this would be extremely vital when huge databases are to be created and consulted regularly for city planning at different scales, particularly satellite images and maps of locations. There is a big need for spatially referenced data creation, analysis, and management. Some of the salient points that this research would be able to definitely contribute with GeoNode, being an open source platform, are facilitating the creation, sharing, and collaborative use of geospatial data. The objective is development of an automated natural hazard zonation system with Internet-short message service (SMS) warning utilizing geomatics for sustainable societies. A concept of developing an internet-resident geospatial geohazard warning system has been put forward in this research, which can communicate alerts via SMS. There has been a need to develop an automated integrated system to categorize hazard and issue warning that reaches users directly. At present, no web-enabled warning system exists which can disseminate warning after hazard evaluation at one go and in real time. The objective of this research work has been to formalize a notion of an integrated, independent, generalized, and automated geo-hazard warning system making use of geo-spatial data under popular usage platform. In this paper, a model of an automated geo-spatial hazard warning system has been elaborated. The functionality is to be modular in architecture having GIS-graphical user interface (GUI), input, understanding, rainfall prediction, expert, output, and warning modules. A simplified but working prototype of the system without the GIS-GUI module has been already tested, validated, and reported. Through this paper, a significantly enhanced system integrated with web-enabled-geospatial information has been proposed, and it can be concluded that an automated hazard warning system has been conceptualized and researched. However, now the scope is to develop it further

Authentication Based on Blockchain

Across past decade online services have enabled individuals and organizations to perform different types of transactions such as banking, government transactions etc. The online services have also enabled more developments of applications, at cheap cost with elastic and scalable, fault tolerant system. These online services are offered by services providers which are use authentication, authorization and accounting framework based on client-server model. Though this model has been used over decades, study shows it is vulnerable to different hacks and it is also inconvenient to use for the end users. In addition, the services provider has total control over user data which they can monitor, trace, leak and even modify at their will. Thus, the user data ownership, digital identity and use of online services has raised privacy and security concern for the users. In this thesis, Blockchain and the e-pass application are studied and alternative model for authentication, authorization and accounting is proposed based on Ethereum Blockchain. Furthermore, a prototype is developed which enables users to consume online services by authenticating, authorizing, and accounting with a single identity without sharing any private user data with the services provider center server. Experiments are run with the prototype to verify that it works as expected. Measurements are done to assess the feasibility and scalability of the solution. In the final part of the thesis, pros and cons of the proposed solution are discussed and perspectives for further research are sketched