Integração de funções de rede virtualizadas e funções de rede físicas

Network Functions Virtualization (NFV) and Software Defined Networking (SDN) have been in the center of network evolution, promising a more flexible and efficient way of managing networks through the on-demand instantiation of network functions (NFs) and reconfigurability of the network as necessary. Nevertheless, as new mechanisms are developed, such technologies require testing before their adoption into real-world deployments. This is where this dissertation contributes, by proposing and evaluating a system architecture that integrates a physical wireless testbed with a cloud-based environment. This allows physical wireless nodes to become part of the cloud environment, enabling its use and configuration as virtual NFs (VNFs). Results showcased the system feasibility, with the testbed being able to instantiate on-demand virtual and physical NFs, in the physical wireless nodes and in an OpenStack data-center.A Virtualização de Funções de Rede e as Redes Definidas por Software têm estado no centro da evolução das redes, prometendo uma forma mais flexível e eficiente de as gerenciar através da instanciação on-demand de Funções de Rede e da sua reconfiguração conforme o necessário. No entanto, à medida que novos mecanismos são desenvolvidos, é também necessário a realização de testes sobre estas tecnologias antes destas serem adotadas em implementações em contexto real. É aqui que esta dissertação contribui, propondo e avaliando uma arquitetura de sistema que integra um testbed físico sem fios, com um ambiente baseado em nuvem. Isto permite que os nós sem fios físicos se tornem parte do ambiente de nuvem, permitindo o seu uso e configuração como Funções de Rede Virtuais. Os resultados demonstraram a viabilidade do sistema, dada a capacidade da testbed em instanciar Funções de Rede virtuais e físicas quando requisitadas tanto nos nós sem fios físicos quanto no servidor OpenStack.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

Comparing reuse practices in two large software-producing companies

Context Reuse can improve productivity and maintainability in software development. Research has proposed a wide range of methods and techniques. Are these successfully adopted in practice? Objective We propose a preliminary answer by integrating two in-depth empirical studies on software reuse at two large software-producing companies. Method We compare and interpret the study results with a focus on reuse practices, effects, and context. Results Both companies perform pragmatic reuse of code produced within the company, not leveraging other available artefacts. Reusable entities are retrieved from a central repository, if present. Otherwise, direct communication with trusted colleagues is crucial for access. Reuse processes remain implicit and reflect the development style. In a homogeneous infrastructure-supported context, participants strongly agreed on higher development pace and less maintenance effort as reuse benefits. In a heterogeneous context with fragmented infrastructure, these benefits did not materialize. Neither case reports statistically significant evidence of negative side effects of reuse nor inhibitors. In both cases, a lack of reuse led to duplicate implementations. Conclusion Technological advances have improved the way reuse concepts can be applied in practice. Homogeneity in development process and tool support seem necessary preconditions. Developing and adopting adequate reuse strategies in heterogeneous contexts remains challenging

MoSIoT: Modeling and Simulating IoT Healthcare-Monitoring Systems for People with Disabilities

The need to remotely monitor people with disabilities has increased due to growth in their number in recent years. The democratization of Internet of Things (IoT) devices facilitates the implementation of healthcare-monitoring systems (HMSs) that are capable of supporting disabilities and diseases. However, to achieve their full potential, these devices must efficiently address the customization demanded by different IoT HMS scenarios. This work introduces a new approach, called Modeling Scenarios of Internet of Things (MoSIoT), which allows healthcare experts to model and simulate IoT HMS scenarios defined for different disabilities and diseases. MoSIoT comprises a set of models based on the model-driven engineering (MDE) paradigm, which first allows simulation of a complete IoT HMS scenario, followed by generation of a final IoT system. In the current study, we used a real scenario defined by a recognized medical publication for a patient with Alzheimer’s disease to validate this proposal. Furthermore, we present an implementation based on an enterprise cloud architecture that provides the simulation data to a commercial IoT hub, such as Azure IoT Central.This work was supported by the Spanish Ministry of Science and Innovation under contract PID2019-111196RB-I00, called “Development of IoT Systems for People with Disabilities” (Access@IoT), and also was partially funded by the GVA through the AICO/2020/143 project

Application development process for GNAT, a SOC networked system

The market for smart devices was identified years ago, and yet commercial progress into this field has not made significant progress. The reason such devices are so painfully slow to market is that the gap between the technologically possible and the market capitalizable is too vast. In order for inventions to succeed commercially, they must bridge the gap to tomorrow\u27s technology with marketability today. This thesis demonstrates a design methodology that enables such commercial success for one variety of smart device, the Ambient Intelligence Node (AIN). Commercial Off-The Shelf (COTS) design tools allowing a Model-Driven Architecture (MDA) approach are combined via custom middleware to form an end-to-end design flow for rapid prototyping and commercialization. A walkthrough of this design methodology demonstrates its effectiveness in the creation of Global Network Academic Test (GNAT), a sample AIN. It is shown how designers are given the flexibility to incorporate IP Blocks available in the Global Economy to reduce Time-To-Market and cost. Finally, new kinds of products and solutions built on the higher levels of design abstraction permitted by MDA design methods are explored

Reconfigurable middleware architectures for large scale sensor networks

Wireless sensor networks, in an effort to be energy efficient, typically lack the high-level abstractions of advanced programming languages. Though strong, the dichotomy between these two paradigms can be overcome. The SENSIX software framework, described in this dissertation, uniquely integrates constraint-dominated wireless sensor networks with the flexibility of object-oriented programming models, without violating the principles of either. Though these two computing paradigms are contradictory in many ways, SENSIX bridges them to yield a dynamic middleware abstraction unifying low-level resource-aware task reconfiguration and high-level object recomposition. Through the layered approach of SENSIX, the software developer creates a domain-specific sensing architecture by defining a customized task specification and utilizing object inheritance. In addition, SENSIX performs better at large scales (on the order of 1000 nodes or more) than other sensor network middleware which do not include such unified facilities for vertical integration