Home networks are evolving vigorously and are also becoming more and more heterogeneous and complex. Home networks contain new services and numerous devices with wired and wireless links. At the same time, users demand high levels of quality of service for many new applications. Hence, the supervision of links quality tends to be mandatory in emergent home networks, to trigger QoS mechanisms. In this context, this dissertation proposes the utilization of the available bandwidth as a performance indicator in hybrid home networks (e.g. for remote service-evaluation, diagnosis and fault detection) and as link-state metric for a number of QoS mechanisms (e.g., admission control, path selection and load balancing). In this dissertation, we firstly explain why available bandwidth probing is a fundamental tool in the new QoS architectures for hybrid home networks and we explore different use cases. We investigate the networking constraints that affect bandwidth probing in hybrid home networks. We explain why most tools to measure available bandwidth on Internet paths are not very efficient on home networks. We make a taxonomic study of a number of state-of-the-art probing techniques and probing tools for available bandwidth. At that aim, we propose a functional framework, called Metrics Profile Capture Filter and Feedback (MPCFF). Based on these studies, we choose Iperf in TCP mode as an attractive tool to estimate available bandwidth. Then, we conduct a performance evaluation on an experimental test bed, to compare Iperf in lightweight TCP-mode vs. various state-of-the-art tools (Wbest, Pathchirp, Pathload and IGI/PTR). We show that Iperf in lightweight TCP mode is superior in terms of accuracy and speed of convergence. Finally, we integrate Iperf in lightweight TCP mode into a path selection protocol using the Inter-MAC software (developed in the Omega European project). We show, on a test bed, how Iperf in lightweight TCP mode enhances the Inter-MAC path selection by eliminating performance deterioration due to time-varying capacity links. Our results show that Iperf in lightweight TCP mode, accurately, triggers path selection and load balancing mechanisms, to adapt the network resources to the strong degradation of WiFi and PLC links. Available bandwidth probing detects and helps to control real-time deviations of the quality of experience, associated of sensitive applications. At the same time, available-bandwidth probing helps the service provider to isolate failures and to monitor the end-to-end residential service, on demand or on long-term periodicity basis.

In this thesis, we study the energy efficient coverage and connectivity problem in wireless sensor networks (WSNs). We try to locate heterogeneous sensors and route data generated to a base station under two conflicting objectives: minimization of network cost and maximization of network lifetime. We aim at satisfying connectivity and coverage requirements as well as sensor node and link capacity constraints. We propose mathematical formulations and use an exact solution approach to find Pareto optimal solutions for the problem. We also develop a multiobjective genetic algorithm to approximate the efficient frontier, as the exact solution approach requires long computation times. We experiment with our genetic algorithm on randomly generated problems to test how well the heuristic procedure approximates the efficient frontier. Our results show that our genetic algorithm approximates the efficient frontier well in reasonable computation times.