Impact of node mobility in user-centric routing

Recent paradigms in wireless communication architectures describe environments where nodes present a highly dynamic behavior (e.g., User Centric Networks). In such environments, routing is still performed based on the regular packet-switched behavior of store-and-forward. Albeit sufficient to compute at least an adequate path between a source and a destination, such routing behavior cannot adequately sustain the highly nomadic lifestyle that Internet users are today experiencing. This thesis aims to analyse the impact of the nodes’ mobility on routing scenarios. It also aims at the development of forwarding concepts that help in message forwarding across graphs where nodes exhibit human mobility patterns, as is the case of most of the user-centric wireless networks today. The first part of the work involved the analysis of the mobility impact on routing, and we found that node mobility significance can affect routing performance, and it depends on the link length, distance, and mobility patterns of nodes. The study of current mobility parameters showed that they capture mobility partially. The routing protocol robustness to node mobility depends on the routing metric sensitivity to node mobility. As such, mobility-aware routing metrics were devised to increase routing robustness to node mobility. Two categories of routing metrics proposed are the time-based and spatial correlation-based. For the validation of the metrics, several mobility models were used, which include the ones that mimic human mobility patterns. The metrics were implemented using the Network Simulator tool using two widely used multi-hop routing protocols of Optimized Link State Routing (OLSR) and Ad hoc On Demand Distance Vector (AODV). Using the proposed metrics, we reduced the path re-computation frequency compared to the benchmark metric. This means that more stable nodes were used to route data. The time-based routing metrics generally performed well across the different node mobility scenarios used. We also noted a variation on the performance of the metrics, including the benchmark metric, under different mobility models, due to the differences in the node mobility governing rules of the models.

Framework para comercialização de soluções de smart cities: o caso PT

Com um número cada vez maior de cidadãos a viver em grandes aglomerados urbanos, as cidades necessitam de se adaptar e tornar mais inteligentes por forma a serem sustentáveis. Desta forma, o conceito de smart city implica a integração de várias dimensões da gestão da cidade, mediante uma abordagem integrada e sustentada, criando um novo mercado per si. Mas, para responder a estas necessidades e conquistar este novo mercado, as empresas têm que se organizar por forma a sustentar as suas decisões estratégicas com ferramentas que permitem a análise e avaliação deste novo paradigma. Baseado nos conceitos de smart cities/cidades inteligentes, este trabalho desenvolve um conjunto de ferramentas que permitem a análise e avaliação de novos mercados pela empresa PTInovação, criando um modelo para a implementação de um mapa de calor/heat map que apresenta as cidades com maior potencial de mercado a nível mundial. Com base neste modelo, é então efetuada uma instanciação do modelo que permite analisar 7 casos diferentes de cidades localizadas na América, África, Ásia e Europa. A partir da análise realizada, é efetuado um caso de estudo para a cidade de Cartagena das Índias, na Colômbia. Este caso de estudo efetua a análise do portfólio de oferta da PTInovação, estuda as necessidades específicas dos utilizadores locais e analisa os potenciais competidores no mercado local, permitindo a realização de uma análise SWOT/TOWS que induz a criação de um plano de ação que permite mapear o processo de entrada da empresa neste mercado.

Context-aware framework for collaborative applications

Future pervasive environments will take into consideration not only individual user’s interest, but also social relationships. In this way, pervasive communities can lead the user to participate beyond traditional pervasive spaces, enabling the cooperation among groups and taking into account not only individual interests, but also the collective and social context. Social applications in CSCW (Computer Supported Cooperative Work) field represent new challenges and possibilities in terms of use of social context information for adaptability in pervasive environments. In particular, the research describes the approach in the design and development of a context.aware framework for collaborative applications (CAFCA), utilizing user’s context social information for proactive adaptations in pervasive environments. In order to validate the proposed framework an evaluation was conducted with a group of users based on enterprise scenario. The analysis enabled to verify the impact of the framework in terms of functionality and efficiency in real-world conditions. The main contribution of this thesis was to provide a context-aware framework to support collaborative applications in pervasive environments. The research focused on providing an innovative socio-technical approach to exploit collaboration in pervasive communities. Finally, the main results reside in social matching capabilities for session formation, communication and coordinations of groupware for collaborative activities.