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The number one smart city in the world uses CEF Context Broker to effectively manage Big Data

For the second year in a row, Vienna ranked first in the Smart City Strategy Index 2019. Learn what lies behind their success and how CEF contributed.


Quick facts

  • Project: VeroCity platform (
  • Location: The City of Vienna, Austria
  • Problem: How to collect and consolidate data for enhanced public services and innovation
  • Solution: A context-aware open data platform that increases transparency and insight
  • CEF Building Block: Context Broker


Behind Vienna’s success

A major contributor to Vienna's top ranking position is the central Smart City Agency dedicated to coordinating and monitoring the success of all projects. This approach has resulted in highly integrated solutions for mobility, the environment, education, healthcare and public administration. For managing one of the biggest challenges for smart cities, big data, Vienna has the VeroCity Platform ( Vienna was actually the first city in the German-speaking world to publish open government data already in 2011, but the platform takes open data to a whole new level. Its data aggregation and analysis capabilities are based on the European Commission’s Context Broker building block, which can sort through data of all sorts and sources from all across the city.

The Context Broker allows the platform to offer real-time information through visual dashboards that cater to the needs of all stakeholders from residents to city officials and software developers. The platform can facilitate day-to-day activities, such as urban mobility, environmental monitoring, urban infrastructure, energy efficiency and more. In addition to the web services offered by the platform, the city’s open data and open interfaces have led to remarkable innovation, as more than 200 new apps have been developed by third-party software engineers.

Data is the new oil – if you can make sense of it

Smart city strategies are often based on big and open data to enhance the city’s quality of life and foster innovation. But sorting through unharmonised data to understand context and interrelationships is time consuming for data engineers. Data can come from many sources and formats, such as legacy systems, users (mobile apps), sensor networks (IoT devices), static datasets (CSV or spreadsheets) and APIs, without any pattern.

Context Broker helps to build pictures

The Context Broker aggregates data and transfers any platform into a context-aware system – turning a spreadsheet of numbers into actionable insight. Let’s use Vienna’s e-bike sharing service as an example to understand how Context Broker made the VeroCity platform smart. The main context data entity in this case is the e-bike sharing station. Context attributes are additional properties of the entity that add critical information, such as the location of the station and the number of e-bikes available. With this knowledge, Context Broker builds a complete picture of the station for actionable insight. 

Screen shot from the VeroCity platform showing information for a Sycube e-bike sharing station.

The dashboard shows that the station has seven bike boxes (see "Station boxes count") with one bike available ("Parked bikes") and six free spots available for returning bikes ("Free boxes"). Further information on individual e-bike usage can be found under Sycube trip data ("Fahrtdaten"). Data on the dashboard is automatically updated every two seconds to provide real-time information on the use of the service provided by a local company, Sycube. This can, for example, allow the city to analyse the use of e-bikes and make policy decisions to enhance mobility. Data visualisation through the dashboard is achieved thanks to Context Broker's data manipulation capabilities.

Benefits for all stakeholders

Citizens and city officials benefit from the platform's web services that can facilitate daily activities from urban mobility to environmental monitoring. The platform gives access to readily organised and visualised information without having to go through raw data. This provides the city unparalleled transparency across policy areas for monitoring and benchmarking, while promoting citizen participation in shaping the future of the city.

For software developers, Context Broker saves time and money with readily available solutions. The APIs make it easy to integrate Context Broker with existing and future systems, they enable cross-sector data interchanges, and facilitate the creation and maintenance of context data models. Context Broker is an open-source solution, eliminating the risk of vendor lock-in. The open-source software, open data and open interfaces also provide opportunities for third-party developers to innovate and get involved in creating smart cities. A complete suite of complementary solutions is provided by FIWARE for data modelling, data visualisation, security, user management and more.

Context Broker at the centre of the solution

VeroCity used Context Broker’s reference implementation, the Orion Context Broker. Orion is an open source software designed to take into account all specifications and save developers time and money. The Context Broker also provides an open standard API to communicate with all other applications in the ecosystem, such as an open government database or a dashboarding application. The API also enables sending data to a historical database, called the Data Lake, for monitoring developments across a timeline. Both Context Broker and the API were developed by the FIWARE association based on the global NGSI specifications. FIWARE’s version of the NGSI interface is a RESTful API that uses HTTP to transfer context data between applications. The API allows data to be retrieved for both one-time queries and subscriptions. The illustration below depicts the solution, with the arrows representing data flows.

Vienna chose relevant data models from FIWARE to define how entities and attributes relate to each other. This helps Context Broker to understand how data can be aggregated from the various different sources, including:

For the API, Vienna chose to use the latest NGSI v2 data model with enhanced support for linked data. This makes it easier to create associations between entities, which facilitates establishing meaningful context for data. A security layer ensures that each stakeholder only sees the data that they are authorized to see. After one year of adapting and customising the solution, it now handles a wide range of data requests with innovative visualisation capabilities based on FIWARE’s complementary business intelligence component, KnowAge. 

Next steps for the platform

Vienna is one of the three European lighthouse cities in the Smarter Together initiative, aiming to improve citizens’ quality of life by finding the right balance between ICT technologies, citizen engagement and institutional governance to deliver smart and inclusive solutions. The VeroCity platform is also used for this initiative to pilot solutions in the district of Simmering in Vienna around three use cases: facility management, monitoring mobility and harmonisation of facility and energy information. Vienna will monitor the results, share them with other cities and upscale finalised solutions throughout the city.

How can Context Broker help you?

If you’re interested in using Context Broker for a project of your own, we would be happy to help you get started. The documentation and support services provided by CEF are described on our website and available to all. 

Last updated on  Jan 26, 2021 11:28
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