Since 2011, the Smart City Expo World Congress has stood as the world’s largest and most influential platform for cities and urban innovation. Hosted annually in Barcelona, it brings together a powerful global ecosystem of leaders from major corporations, national governments, research institutions and strategic organizations that are actively shaping the next era of urban development.
In this first instalment of the Smart City series, we explore what truly defines a “smart city,” the systems and principles that make it work, and why people, not machines, must remain at its core. With the recent 2025 conference staging offering a vivid display of global innovation and practical implementation, Barcelona provided the perfect backdrop for examining both the tremendous promise and the profound responsibility involved in building the cities of tomorrow.
Defining A Smart City
According to a 2025 Market US’s Smart City Statistics Report, a smart city is an urban area that leverages data, digital technologies, and connected infrastructure to improve residents’ efficiency, sustainability, and quality of life. Similarly, AutoPi’s 2025 overview on smart-city technology defines it as an ecosystem where information and communication technologies enhance urban performance, reduce emissions, and deliver better public services. In simple terms, a smart city is not about gadgets or surveillance, it is about connecting technology, governance, and community to make life better for people.
Barcelona’s Smart City Expo World Congress
According to official data from Fira de Barcelona, this year’s Smart City Expo World Congress held November 4-6, attracted over 27,000 visitors from 130 countries, along with 1,100 exhibitors, 600 speakers, and representatives from more than 850 cities. Rome was awarded Smart City of 2025 for its “Rome: The City Is Transforming” initiative, which uses 5G, data integration, and digital twins to improve governance and public services ahead of the 2025 Jubilee. As stated by Ugo Valenti, Director of the Congress, “Across Europe and around the world, cities are proving that cooperation is our strongest tool for progress. We need shared strategies that unite technology, policy, and people to deliver tangible improvements in urban life.”
The event also recognized Kuala Lumpur’s Mayor Maimunah Mohd Sharif with the Leadership Award for advancing global urban innovation, and honored projects from India, Brazil, South Korea, Belgium, China, Saudi Arabia, and the U.S., underscoring the truly global scale of the movement.
The Core Elements Of A Smart City
- According to Capgemini’s “Trends in 2025 for Smart Cities” report, the first essential layer of any smart city is connectivity and infrastructure, built on technologies such as IoT sensors, digital twins, 5G networks and edge computing. These systems allow an urban environment to sense what is happening, process information rapidly and make informed, real-time decisions.
- IoT sensors are small connected devices placed throughout the urban landscape — on roads, buildings, utility lines and public spaces, that collect continuous data on traffic patterns, air quality, water leaks, energy use and safety conditions.
- Digital twins are highly detailed virtual replicas of real-world assets, from single buildings to entire transit corridors. They allow planners to simulate scenarios, detect risks early and optimize infrastructure without disrupting daily life.
- 5G networks provide ultra-fast, low-latency connectivity capable of supporting millions of devices simultaneously. This enables advanced applications such as autonomous mobility, real-time public safety tools and responsive energy grids.
- Edge computing processes data closer to where it is generated, at a traffic signal, substation or sensor hub, rather than relying solely on the cloud. This dramatically reduces delays and supports time-critical operations.
Together, these technologies create the digital nervous system of a smart city, enabling faster decisions, more efficient resource use and better services for residents.
2. The second is data-driven governance. At this level, city administrators would be able to use analytics to optimize everything from waste-collection routes to traffic-signal timing and energy-grid stability and cutting both costs and carbon footprints.
3. The third pillar is citizen inclusion and ethics, a dimension where many urban transformations succeed or fail. Research shows that when residents are excluded from design, governance and data-decision processes, the result is a stratified urban environment often referred to as a two-tiered city. According to a 2024 study called Smart Cities, Digital Inequalities, and the Challenge of Inclusion, new smart-city initiatives have deepened social and digital inequalities by privileging tech-savvy, younger and higher-income residents while leaving older, less skilled or financially vulnerable individuals “digitally invisible.”
A two-tiered city is characterized by one urban group that enjoys high-quality digital connectivity, seamless access to services, and meaningful participation in urban decisions, while another group faces limited or no access, weak digital literacy, and little say in how systems are designed. According to a Nature-published study of 181 European cities, higher “smart-city” rankings were still associated with persistent digital divides, particularly in ownership and usage of devices among lower-income or minority residents. In practical terms, this means that even cutting-edge infrastructure, sensors and data platforms will not deliver inclusive benefit unless the governance framework ensures equal access, transparent data practices, and active citizen engagement.
If digital exclusion and opaque surveillance systems prevail, cities risk perpetuating inequality rather than alleviating it. That risk becomes structural in a two-tier city: rich in digital services for some, poor in access and voice for others. The ethical imperative in smart-city design is therefore clear, that inclusion must be built in from day one and not as an after-thought.
4. Finally, sustainability and resilience. According to the UN Sustainable Development Goals framework SDG 11, cities consume up to 60–80 percent of global energy and generate 75 percent of carbon emissions. Therefore, embedding climate adaptation and renewable integration within smart-city design is non-negotiable.
Promise And Perils Of A Smart City
While the promise of smart cities is immense, the perils are real and concerning. According to a 2023 article Privacy and Security Concerns in the Smart City, the surge in data collection and Internet of Things deployment has already produced serious privacy and security risks: the authors warn of “hazard and damage” in urban systems where tracking technologies can be abused, and they note that current legal remedies are “insufficient” to handle these possibilities.
According to the Smart Cities and Democratic Vulnerabilities report, most municipal smart-city ICT projects carry risks related to the handling of personal data and are frequently implemented without human rights impact assessments. The study details how systems once designed to enhance efficiency, such as facial recognition and big-data dashboards can instead augment authoritarian control, deepen social divides and erode democratic accountability.
According to a 2024 Nature commentary on “Digital Surveillance Capitalism and Cities”, the erosion of data sovereignty in urban ecosystems is a “critical juncture” in development; platforms built for citizen services are increasingly being repurposed as tools of extraction, not empowerment.
These dynamics give rise to the aforementioned term “two-tiered cities” where on one side, highly connected populations with full access to smart services; on the other side, communities left behind by a lack of infrastructure, digital literacy or transparency. When digital exclusion merges with opaque surveillance systems and data monopolies, urban innovation can become a mechanism of control rather than liberation. Unless rigid safeguards, ethical governance and citizen-centric design are embedded from the start, smart-city projects risk reinforcing inequality, undermining privacy and even enabling sub-democratic governance.
The Smart City Question: Where Do We Go From Here?
As cities accelerate toward a more connected, data-driven future, the smart-city agenda sits at a defining crossroads. Around the world, the benefits are undeniable: cleaner energy systems, faster emergency response, smoother mobility, stronger climate resilience and services that are more efficient, predictive and accessible. At the same time, the risks are equally clear. Uneven access, opaque data practices, growing surveillance capabilities and widening digital divides have shown that technology alone cannot guarantee fairness or trust.
What the evidence from Barcelona makes unmistakable is that smart cities are neither inherently utopian nor inherently dystopian, they are shaped by the values, governance choices and safeguards we build into them. Technology can elevate a city or fracture it. It can democratize opportunity or silently harden inequalities. It can expand freedoms or compromise them.
The future of urban innovation will depend not on sensors, networks or algorithms, but on how intentionally we design the systems behind them, and how deeply people remain at the center of every decision.
Whether a smart city becomes a catalyst for inclusion or a catalyst for inequity is not yet predetermined. It is a question each society, each government and each resident must answer. Perhaps that is the real invitation of this moment is to look at the promise, acknowledge the peril, and decide collectively what kind of cities we want to build next.
