Toward the Sentient City with Snap4City


Warning message

You can't delete this newsletter because it has not been sent to all its subscribers.

Article by: Raffaele Nicolussi, February 7, 2019

Originalli published on:

A sentient city knows what it has and makes decisions based on current, accurate and shared information.

In the smart city, databases become real sensors, able to detect daily variations in the life of buildings, citizens, companies, consumption, etc.

The challenge of the smart city lies in the complexity of managing heterogeneous data

The intelligent city is a place where digitised map data is mashed up and integrated with information coming from different public bodies (municipalities, Land Agency, chambers of commerce, service companies, etc.), with the data collected by sensors (data collectors for weather, air quality, electronic meters, traffic, video surveillance, etc.), with comments posted on Facebook, tagged on Flickr or tweeted on Twitter.

The challenge of the smart city lies in the complexity of managing heterogeneous data, which, as seen, can come from a variety of sources, creating an integrated and transversal model.

The integration of such data encourages expansion of knowledge and reduces reaction time compared to the occurrence of facts on the territory: the real challenge is, therefore, to develop integration platforms which can intelligently manage all this data. Today we will talk about a platform designed for this purpose.

Snap4City (scalable Smart aNalytic APplication builder for sentient Cities) is a fully open source, data-driven, scalable platform based on cloud,

Snap4City (scalable Smart aNalytic APplication builder for sentient Cities) is a fully open source, data-driven, scalable platform based on cloud, which, through the analysis and aggregation of large amounts of data and the use of Artificial Intelligence algorithms, is able to offer important services such as detection of anomalies, early warnings and environmental risk assessment.

The platform enables stream and batch processing and is completely realised through microservices and by using easily replaceable tools, which make it scalable, flexible, safe and respectful of privacy, endowed with a powerful semantic reasoner.

Snap4city is developed by the DIstributed Systems and Internet Technologies Lab (DISIT) of the University of Florence, a research laboratory specialising in IOT / IOE technologies, distributed systems for high performance, distributed and parallel computing, big data, data analytics, smart cities, semantic computing, expert systems, NLP and the smart cloud. It is definitely a reference platform, used for experimentation across many projects and areas.

It is also a Living Lab, a system based on a systematic co-creation approach, integrated innovation and research processes that lead to engaging users and making them sources of creation. The Living Lab allows operators as well as end users to develop their IOT applications, dashboards, data analytics in the cloud or, on IOT Edge, making full use of communication technologies and the cloud.

Img.1 – Scheme of Snap4City framework and modules.

The semantic reasoner on which Snap4City is based is Km4City, a multi-domain semantic model and tools. Born in 2013 as an ontology for smart cities, its aim is to improve quality of life by enabling the creation of innovative services for cities with a particular focus on mobility, security, tourism and the reduction of consumption and cost.

At the moment, Km4City, a knowledge base for services of various projects, spans the whole of Tuscany with its data, in terms of road information, points of interest, public transport services, gas stations, information on hospital triage, traffic flows and much more to come.

The Snap4City platform offers many features, such as data acquisition from sources of any kind and with various protocols, their aggregation with a unified Km4City model, automatically reconciling complex data, data analytic even in streaming and displaying them directly in interactive Dashboard, on mobile or on other devices. Moreover, Snap4City highlights connections in the IoT / IoE End-to-End environment, secure and encrypted by any type of IoT Device. Furthermore, the proposed solution responds perfectly to the aims of the “Fourth Industrial Revolution“, Industry 4.0, the industrial automation process which aims to improve working conditions through the use of innovative technologies.

Img.2 – Interaction between sensors and data collector/analysis tools. 

The following figure shows the Snap4City development environment through which an IoT Application of an IoT Edge is edited. The flows must be read from left to right and can present corresponding virtual or physical elements, IoT devices, such as buttons or virtual elements in the Dashboard.

Img.3 – Example of development environment for Iot with Node-RED

Snap4City also lends itself to analysis in the energy field, allowing the user to easily create systems that can handle large amounts of data which can be analysed in real time. As an example of its application in this field, a prototype has been realised that includes a data acquisition system, a load generation system, a storage system on a MONGO Federated NoSQL storage and an indexing system based on Elastic Search. The results produced were represented in real time through Kibana (an open source data visualization plugin for Elasticsearch). The following figures show a Dashboard created through the Dashboard Builder of Snap4city in Smart City, the first, and Industry 4.0, the second.

Img.4 – Example dashboard from real data on traffic.

Img.5 – Example dashboard from real data on energy consumption.


Snap4City platform and solutions are available at website, you can register and start exploring its features. But if you want to really challenge your skills and propose your innovative solutions for connected cities, you can join the upcoming Snap4City Hack, the big online hackathon on the topics of Smart City and IoT.

Snap4City launched a big online Hackathon on Ecological Watch, Social and Service Evolution, Stimulating Business Growth, City Aware. 

Using Snap4City tools to manage IoT, Big Data, and analytics, the hackathon challenges will cover different themes – Ecological Watch, Social and Service Evolution, Stimulating Business Growth, City Aware – and real data from cities such as Helsinki or Antwerp.

Further information on the Hackathon is available on the on website.