Our world is digitized everyday and increasingly. In 2020, it is expected that over 70% of the population will live in or around cities. To guarantee a good quality of life, it is necessary to ensure fast and reliable services in all areas, in particular those which are mainly based on the use of connected objects. This is one of the cornerstones of a smart city project. It will make possible to provide close to real-time the remote monitoring of sick patients, the monitoring of the environment in order to know its evolution over time and to anticipate developments that can be harmful to health and the environment itself, and to accurately analyze the signals transmitted by the on-board sensors. To further develop domains such as eHealth or the monitoring of other networks in the context of Smart Cities, fast and reliable design tools are needed. Their objectives are to study the realizability of such networks, their behavior in terms of energy consumption, safety, cost and other reliability parameters. This keynote aims to present a new platform called CupCarbon that allows to design systems of connected objects mainly representing sensors and to prepare future deployments of large-scale IoT infrastructures for Smart cities in optimal conditions. This kind of platforms will be a part of systems in the world that will participate in the generation of Big Data.