The main goals of a smart-city are to improve sustainability and livability, to ease city government and organization, and to increase services to the citizens. The primary role of ICT in enabling this vision is to keep the decision makers, the stake holders and the citizen constantly updated with fresh information collected around the city. To accomplish this task, next generation cities, will be populated with billion of heterogeneous devices ranging from tiny communicating objects (e.g., actuators, sensors, tags) able to interact with the surrounding environment and remote systems, to high-end nodes (e.g., data centers, workstations) capable of complex operations and to process an huge amount of information. In this futuristic scenario a very special role is played by citizens with their smartphones, tablets and portable devices. They are constantly connected with whatever surroundings them and they are formidable information consumers. At the same time, citizens roaming around the city may be considered as mobile probes which, by making uses of cyber and physical data accessible by smartphones, can analyze the situation and produce reports to the community. Furthermore smartphones can actively contributing in creating the communication infrastructure by forwarding data coming from surrounding devices. All in all, cities are going to become a new complex ecosystem which has the potentiality to offer many amazing features and support innovative application. Unfortunately, fully exploiting, managing and accessing that ecosystem are still far to be fully viable and their fulfillment surely poses a formidable challenge. The SWANSITY workshop aims to solicit contributions on novel algorithms, methodological studies and experimentations on how to enable the formerly described ecosystem. Specifically, on how devise a city-wide networking infrastructure capable to efficiently guarantee communication in the new envisaged ecosystem, to manage the complexity of heterogeneous devices and access technologies, and to guarantee robust, ubiquitous, and secure connectivity over the urban environments.