The 5 Layers of the Smart City

by Anders Lisdorf

When we say we want our future cities to be smart, what we really mean is that we want to use technology to make our cities more effective, resilient, sustainable, and safe. We don't want to have to queue in line for hours to speak to a government official or walk through smog infested streets where we can't drink the water from the tap. That is not smart. The smart city is a beacon of a utopian future.

However, the details of what, how, when, and with whom we create this smart city is much more tenuous. There is no dearth of vendors and pundits interested in the smart city willing to supply their own angle on this. While this can be inspirational, one often loses sight of the bigger picture. Today many cities find themselves unable to truly harness the potential of the smart city technologies available. In order to maintain the orientation and focus on a practical way to make cities smarter it can help to focus on five distinct layers of the smart city that need to be understood and managed.


A precondition for making technologies smart is that they can be connected. Networks are much more than just something the infrastructure network engineer is responsible for. Networks are also social networks, relationships, organizations, and so on. Networks come in different forms and sizes with very different properties. Understanding the structure and properties of networks is important for designing connection solutions that support the goals of the city. For example, do we want a resilient network at any price, or do we want centralized control? These two things are not generally compatible.

But networks are also technical networks⁠—wired or wireless⁠—that come in many different variants. The cellular and wifi networks have become a mainstay of popular culture and used by virtually everyone living in the city. Nevertheless, a vast underground of different types of networks are becoming more widespread. Some have ranges one-hundred-fold of cellular and wifi while others support very low energy transmission that allows the device to run on batteries for years or even decades. Understanding and choosing the right network for the job is becoming an increasingly important part of the smart city.


Different devices serve different purposes and come in many different shapes and sizes. They are so much more than just the phones, watches, and tablets that we know. Everything from tiny pace makers to industrial components can be categorized as devices. There are two primary groups: sensors and actuators. The sensors measure aspects of their environment. That could be temperature, humidity, air quality, or movement. These signals from the environment are translated into electrical signals, which can in turn be transformed to data that can be sent to a receiver. Actuators change their environment typically through movement. A basic example of a sensor and actuator is the automatic sliding door where a movement sensor registers movement and an actuator slides the doors apart. Actuators also open and close valves in watering systems and drive the limbs of robots.


The raw material of the smart city is data. While data is ubiquitous, it is like oil: something that needs to be extracted and refined in order to be useful. Data comes from many different sources in the city. At one end of the scale are systems of record where we find registrations made by city employees and through self service. At the other end is log data and measurements from sensors. These types of data have very different structures and need to be managed differently. They also have different volumes and velocities, which adds to the complexity of managing the data. It is helpful to think of managing the data along the oil metaphor and plan for building a data refinery. The key area of focus, however should always be to improve the value and utility of the data. Data you cannot get to or which is unintelligible will forever remain worthless even if it has high data quality.


What puts the "smart" in smart cities is intelligence⁠—more precisely, artificial intelligence or machine learning. While full-fledged artificial intelligence in the form of neural networks may be rarer, good old fashioned algorithms already penetrate many automated and semi-automated processes. The growing public interest and concern has only exacerbated the need for a more principled and transparent approach. Thinking about how, where, and why algorithms are used in the life of the city is taking center stage. It is necessary to form opinions and understand fairly complex technical issues in order to manage the intelligence layer of the city. Doing this, however, is important in order not to end up in technoskepticism and miss out on important opportunities offered by advanced algorithms. On the other hand, it is also pertinent to not fall into a technocratic state where residents are left in the dark with no influence over how technology controls ever larger parts of their life.


The smart city does not spring to life fully formed knowing its different layers. The city needs to engage with multiple different groups of stakeholders. It is very rare that a city has all the resources it needs to develop and manage all technological solutions, for the simple reason that the areas of application are so diverse. Consequently, the city is dependent on a wide variety of groups of people. Vendors create solutions on-demand, while universities engage with the city on joint research projects. Residents themselves are also becoming more engaged, expect to be heard, and want to participate in developing technology for the good of the city. By understanding how the city can engage with different stakeholder groups, it is possible to create innovative solutions that make the city a little smarter.

Stitching the layers together

Like layers in any enterprise architecture, these five layers need to come together in actual solutions. Awareness of these distinct layers can help us categorize, standardize, and build policies and frameworks to support it. For each layer we need to decide what we want. What kind of networks do we want in order to support the city? How do we relate to algorithms affecting people's lives? What kind of security do we require for devices in our city? Reflections on the five layers are central to the sustained success of the smart cities of the future. We need to focus on what kind of connection we want, how to handle and secure devices, extract and refine data, build intelligence into the solutions, and find the right forms of engagement. Having a basic idea and plan for the five layers of the smart city will help cities to start building smarter cities.

About the Author

Anders Lisdorf has worked with innovative technologies for more than a decade in many different settings and industries. The last couple of years he has been responsible for developing the data services of New York City, but previously he has worked as an entrepreneur, taught at the university level and worked as a consultant. 

This article was contributed by Anders Lisdorf, author of Demystifying Smart Cities.