88 research outputs found
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Towards Trouble-Free Networks for End Users
Network applications and Internet services fail all too frequently. However, end users cannot effectively identify the root cause using traditional troubleshooting techniques due to the limited capability to distinguish failures caused by local network elements from failures caused by elements located outside the local area network.
To overcome these limitations, we propose a new approach, one that leverages collaboration of user machines to assist end users in diagnosing various failures related to Internet connectivity and poor network performance.
First, we present DYSWIS ("Do You See What I See?"), an automatic network fault detection and diagnosis system for end users. DYSWIS identifies the root cause(s) of network faults using diagnostic rules that consider diverse information from multiple nodes. In addition, the DYSWIS rule system is specially designed to support crowdsourced and distributed probes. We also describe the architecture of DYSWIS and compare its performance with other tools. Finally, we demonstrate that the system successfully detects and diagnoses network failures which are difficult to diagnose using a single-user probe.
Failures in lower layers of the protocol stack also have the potential to disrupt Internet access; for example, slow Internet connectivity is often caused by poor Wi-Fi performance. Channel contention and non-Wi-Fi interference are the primary reasons for this performance degradation. We investigate the characteristics of non-Wi-Fi interference that can severely degrade Wi-Fi performance and present WiSlow ("Why is my Wi-Fi slow?"), a software tool that diagnoses the root causes of poor Wi-Fi performance. WiSlow employs user-level network probes and leverages peer collaboration to identify the physical location of these causes. The software includes two principal methods: packet loss analysis and 802.11 ACK number analysis. When the issue is located near Wi-Fi devices, the accuracy of WiSlow exceeds 90%.
Finally, we expand our collaborative approach to the Internet of Things (IoT) and propose a platform for network-troubleshooting on home devices. This platform takes advantage of built-in technology common to modern devices --- multiple communication interfaces. For example, when a home device has a problem with an interface it sends a probe request to other devices using an alternative interface. The system then exploits cooperation of both internal devices and remote machines. We show that this approach is useful in home networks by demonstrating an application that contains actual diagnostic algorithms
A fault fuzzy-ontology for large scale fault-tolerant wireless sensor networks
International audienceFault tolerance is a key research area for many of applications such as those based on sensor network technologies. In a large scale wireless sensor network (WSN), it becomes important to find new methods for fault-tolerance that can meet new application requirements like Internet of things, urbane intelligence and observation systems. The challenge is beyond the limit of a single wireless sensor network and concerns multiple widely interconnected sub networks. The domain of fault grows considerably because of this new configuration. In this context, the paper proposes a fault fuzzy-ontology (FFO) for large scale WSNs to be used within a Web service architecture for diagnosis and testing
Uma solução de implantação auto-adaptativa para plataformas Android
Orientador: CecÃlia Mary Fischer RubiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Os dispositivos móveis, hoje em dia, fornecem recursos semelhantes aos de um computador pessoal de uma década atrás, permitindo o desenvolvimento de aplicações complexas. Consequentemente, essas aplicações móveis podem exigir tolerar falhas em tempo de execução. No entanto, a maioria das aplicações móveis de hoje são implantados usando configurações estáticas, tornando difÃcil tolerar falhas durante a sua execução. Nós propomos uma infraestrutura de implantação auto-adaptativa para lidar com este problema. A nossa solução oferece um circuito autônomo que administra o modelo de configuração atual da aplicação usando um modelo de caracterÃsticas dinâmico associado com o modelo arquitetônico da mesma. Em tempo de execução, de acordo com a seleção dinâmica de caracterÃsticas, o modelo arquitetônico implantado na plataforma se re-configura para fornecer uma nova solução. Uma aplicação Android foi implementada utilizando a solução proposta, e durante sua execução, a disponibilidade de serviços foi alterada, de tal forma que sua configuração corrente foi dinamicamente alterada para tolerar a indisponibilidade dos serviçosAbstract: Mobile devices, nowadays, provide similar capabilities as a personal computer of a decade ago, allowing the development of complex applications. Consequently, these mobile applications may require tolerating failures at runtime. However, most of the today¿s mobile applications are deployed using static configurations, making difficult to tolerate failure during their execution. We propose an adaptive deployment infrastructure to deal with this problem. Our solution offers an autonomic loop that manages the current configuration model of the application using a dynamic feature model associated with the architectural model. During runtime, according to the dynamic feature selection, the deployed architectural model can be modified to provide a new deployment solution. An Android application was implemented using the proposed solution, and during its execution, the services availability was altered so that its current configuration was changed dynamically in order to tolerate the unavailability of servicesMestradoCiência da ComputaçãoMestre em Ciência da Computação131830/2013-9CNP
A Model-driven Architecture for Multi-protocol OBD Emulator
The Internet of Things (IoT) might be the next revolutionary technology to mark a generation. It could have a particularly strong influence on the automotive industry, changing people’s perception of what a vehicle can do. By connecting several things in a car, IoT empowers it to sense and communicate. Furthermore, this technology clearly opens the way to emerging applications such as automated driving, Vehicle-to-Vehicle and Vehicleto-Infrastructure communication.
Vehicle’s information about its environment and surroundings is crucial to the development of existing and emerging applications. It is already possible to communicate directly (on-site) with vehicles through a built-in On Board Diagnostics (OBD), making it possible to obtain crucial information about the state of the vehicle in real environments. However, there is zero tolerance for error when developing new applications for vehicles that are, a priori, extremely costly and that must also safeguard human lives. Therefore, there is an increasing need for OBD emulators which can allow the development of new applications.
This Thesis proposes a model-driven architecture for multi-protocol OBD emulator, encouraging the development of new emerging OBD systems in a safety environment, to promote the creation of applications to interact or use vehicles’ data. In this sense, the addressed specifications are: Less expensive comparing with today’s solutions; Compatible with different OBD protocols communication; Open Source Hardware and Software suitable for Do-It-Yourself (DIY) development
Policy-based management of medical devices and applications
Die Arbeit präsentiert einen erweiterten Ansatz zum autonomen technischen Management, der das innovative Modell-basierte Management mit dem etablierten Policy-basierten Management kombiniert. Zur Planung des Systems wird ein umfassendes Modell des Management- und des zu verwaltenden Systems entworfen. Beide Systeme werden auf drei Abstraktionsschichten („Use Cases“, „Services“, „Components“) modelliert. Auf Basis der vorgestellten Ableitungsmuster (Evaluierungs-, Kontroll- und Verfeinerungsmuster) und der Zwischenschichtassoziationen wird der Prozess der Ableitung der Management-Policies automatisiert mit Hilfe eines Modellierungstools durchgeführt. Am Ende werden die zur Laufzeit vom Management ausführbaren Policies generiert. Der Ansatz wird im Rahmen des medizinischen Anwendungsfeldes erprobt. Es wird gezeigt, dass der Ansatz die Entwicklung und Verlässlichkeit sowie den Betrieb des medizinischen Geräte- und Anwendungsensembles unterstützt.This work presents an extended approach to the autonomous technical management, which combines the innovative model-based management with the established policy-based management technique. A comprehensive model of the managed and the management system is created. Both systems are modeled on three abstraction layers („Use Cases“, „Services“, „Components“). On the basis of the introduced policy derivation patterns (evaluation, control and refinement patterns) and intra-layer associations the policy derivation process is conducted automated by means of a modeling tool. Finally, runnable policies are generated which are enforced by the management at runtime. The approach is applied within the medical application field. It is demonstrated, that the presented technical management supports the development and dependable behavior of medical devices and applications
Carbook: A Platform for Mobile Automotive Services
Wireless mobile technologies have triggered a rapid development of secondary network technologies. One such prominent field of technology is interoperability for consumer devices. This field is mostly based on XML and Web Services and it includes technologies such as Universal Plug-and-Play, open media container formats, open codecs and Rich Internet Application technologies for mobile devices.
Automotive field has been relatively slow and conservative in embracing these new Internet technologies. This is about to change as European Union and other substantial players are pressing forward with the safety and environmental technologies in cars. These technologies depend heavily on wireless Internet connectivity.
As part of this thesis work, I have played a central role in defining the core concept of a distributed framework for mobile automotive services, Carbook System. I have also outlined the first phase of a shared research environment, Carlab, for these kinds of services. Carlab is used to demonstrate different technologies in accordance to Elektrobit’s vision for the future automotive Internet services. Carbook System will be implemented incrementally jointly with the continuation of the Carlab implementation.
In this master of science thesis I have mapped and evaluated the essential technologies and created a preliminary outline for Carbook System and a set of services. The first phase Carlab network topology and emulation of different domains in Carbook System are also drafted in this thesis work
Architecting Social Internet of Things
In the new era of the Internet of Things (IoT), most of the devices we interact with daily are connected to the Internet. From tiny sensors, lamps, home appliances, home security systems and health-care devices, to complex heating, ventilation and air conditioning (HVAC) systems at home, myriad devices have network connectivity and provide smart applications. The Social Internet of Things (SIoT) is a new paradigm where IoT merges with social networks, allowing people and connected devices as well as the devices themselves to interact within a social network framework to support a new social navigation. Smart homes is one of the domains that can fully leverage this new paradigm, which will enable people and devices, even in different homes, to actively and mostly automatically collaborate to discover and share new information and services. Unfortunately the heterogeneous nature of the devices around the home prohibits seamless communication in the (S)IoT. Furthermore, the state-of-the-art solutions in smart homes offer little, if any, support for collaborating users and devices. This dissertation describes a new, scalable approach to connect, interact and share useful information through devices and users with common interests. The dissertation has three contributions. First, it proposes a holistic and extensible smart home gateway architecture that seamlessly integrates heterogeneous protocol-- and vendor-- specific devices and services and provides fine-grained access controls. Second, it defines an interoperable, scalable and extensible software architecture for a novel cloud-based collaboration framework for a large number of devices and users in many different smart homes. Third, it provides a reasoning framework to enable automated decisions based on the discovered information and knowledge created and shared by end users. The developed architecture and solutions are implemented in real systems, which integrate with many different devices from different manufacturers and run multiple categories of rules created by end users. The architectural evaluation results show the developed systems are interoperable, scalable and extensible
MC^2S: a Mobile Component-based CrowdSensing framework
CrowdSensing often refers to sharing data collected by sensing devices with the aim of measure a phenomena of common interest. Within this thesis we will describe MC^2S, a novel Component-based framework suitable for the easy development of multiple, secure, portable, interopeable and concurrent MCS applications. The framework has been built in collaboration between University of Pisa and Trinity College Dublin, starting from September 2015. It exploits both Apache Felix implementation of OSGi framework specifications to ensure composite applications and Java environment to guarantee portability over an huge range of heterogeneous hardaware. However, even if MC^2S framework already offers several forefront capabilities, a lot of additional features may be introduced during the development of its next versions
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