Since 1950, the number of people living in cities has risen almost six-fold to over 4 billion. That number is projected to increase by another 2.5 billion, by 2050. The smart city, coupled with the Internet of Things (IoT), is one of the most promising technologies to address the severe strain that this rapid population growth imposes on the public services and infrastructure of cities.

A smart city uses Internet of Things (IoT) sensors in urban areas to collect data and automate systems such as traffic, energy use, and waste management. By doing so, smart cities improve the efficiency of urban services, reduce costs, and deliver a higher standard of living.

Dgtl Infra takes a deep dive into the different IoT technologies that are fundamental building blocks of a smart city, as well as the innovative applications that result. Smart cities are increasingly using IoT technologies to collect data and develop insights to manage assets, resources, and services more efficiently. Furthermore, this shift is being accelerated by the combination of increased data speeds and capacity capabilities of wireless and wireline networks, as well as emerging IoT applications.

What is a Smart City?

A smart city incorporates advanced technology, including a vast network of sensors and interconnected devices, which gather real-time information to improve the efficiency of public services, while saving money and resources.

While it is difficult to determine where the world’s first smart city was established, given that different people have different definitions for what constitutes a smart city, Songdo in South Korea – which is located ~25 miles southwest of Seoul – is often cited as one of the earliest examples of smart city initiatives. Today, more than 2/3rds of cities globally are investing in smart city technologies.

According to Grand View Research, the global market size for smart cities comprised revenue of $1,227 billion in 2022. Furthermore, the smart cities market size is forecasted to increase at a 25.8% compound annual growth rate (CAGR) from 2023 to 2030, reaching $6,965 billion of revenue by 2030.

Smart City Initiatives

While smart cities may appear in different forms, they are mainly characterized by one or more of the following initiatives: intelligent transportation, smart buildings, smart energy grids and meters, smart governance, smart healthcare, smart public safety, and environmentally-friendly policies.

Notably, a smart city is not a single entity. Rather it is a combination of different smart solutions integrated together to improve the quality of life in that city. Typically, smart cities are built through partnerships between public and private sectors.

Smart City Technologies

Smart cities utilize several enabling technologies to provide intelligent services to their citizens. These include IoT technologies, big data and analytics, edge computing, regional data centers, 5G networks, cloud computing, artificial intelligence (AI) & machine learning (ML), blockchain, and robotics.

Smart City Examples

Around the world there are a number of smart cities, each pursuing their own smart city initiatives:

  • Singapore: operates a city-wide network of sensors and cameras to monitor traffic, weather, and pollution
  • Amsterdam: uses a digital twin to simulate and test urban planning decisions before they are implemented in the real world
  • San Diego: implemented a number of smart grid initiatives, including a smart street lighting system and a system for managing the flow of electric vehicles (EVs)
Top 10 Smart Cities in the World
CityIndex Score
New York70.4
Source: Statista.

Internet of Things (IoT) and the Smart City

The Internet of Things (IoT) refers to the network of physical objects, such as devices, vehicles, and buildings, embedded with sensors, software, and connectivity, which enable them to collect and exchange data. These connected devices can communicate with other devices and systems, allowing them to function and share data seamlessly.

Together, IoT and the smart city are being used to efficiently address the escalating demands for resources of so many residents living, working, driving, and interacting with each other. For example, IoT and smart city initiatives are being applied to the improvement of traffic management, energy consumption, public safety, healthcare, and more.

Worldwide, there are expected to be 74.5 billion IoT connected devices by 2025 and $189.5 billion of smart city spend in 2023.

IoT forms the technical backbone of every smart city in the world, equipping them with the intelligence, interconnection, and instruments needed to improve urban services, optimize resources, and reduce costs. By connecting various devices, systems, and people, IoT can provide real-time data and insights on city operations and infrastructure.

However, there are some distinct challenges in fully realizing the vision of a smart city – with security being the biggest concern at present. To this end, the interconnectedness of IoT devices creates new vulnerabilities for cyberattacks, data breaches, and unauthorized access.

READ MORE: Internet of Things (IoT) Security – Next-Generation Protection

Another major concern is the scalability of IoT infrastructure. As the number of IoT devices in a city is rapidly increasing, the amount of data generated is also quickly growing, putting a strain on existing IoT systems.

READ MORE: Internet of Things (IoT) Devices – What’s Smart in 2023?

IoT Technologies for Smart Cities

The foundation of smart cities relies on the utilization of Internet of Things (IoT) devices and networks. These devices, in combination with software solutions, user interfaces, and communication networks, enable and enhance the functioning and efficiency of smart cities.

Ultimately, the goal is to have IoT technologies interconnected, with data flowing seamlessly between devices, in order to create a truly smart city that can improve quality of life. More specifically, these IoT technologies include radio-frequency identification (RFID), near-field communication (NFC), low-power wide-area (LPWA), wireless telecommunications, wireless sensor network (WSN), DASH7, and addressing.

Radio-Frequency Identification (RFID)

Radio-frequency identification (RFID) tagging devices use radio frequencies to transfer data, mainly to track and identify objects and people. In a smart city, tracking the location and movement of vehicles, equipment, and even people can generate important data that can be used to optimize the operation of transportation systems, waste collection routes, and parking availability.

Additionally, RFID technology can be used to improve security and public safety in a city by enabling real-time tracking of vehicles and individuals.

Near-Field Communication (NFC)

Near-field communication (NFC) is a set of standards for smartphones and other devices – like credit card readers – to establish radio communication with each other by bringing them into close proximity, typically within an inch (or a few centimeters). In smart cities, NFC is used for bidirectional short-distance communication, such as contactless payments, access control, and electronic ticketing.

Low-Power Wide-Area (LPWA)

Low-power wide-area (LPWA), in licensed spectrum, is an optimal solution for IoT applications that require low-power, low-cost, and low-bandwidth communication. At the same time, LPWA technologies benefit from battery life of ~10 years.

In a smart city, LPWA networks are used in applications such as building automation and industrial automation – part of the Industrial Internet of Things (IIoT).

Wireless Telecommunications

3G, 4G Long-Term Evolution (LTE), and 5G are cellular wireless telecommunications standards that have been primarily used by mobile phones and data terminals. Importantly, 5G offers lower latency, increased speed, higher density (# of connected devices), added capacity (network throughput), and energy efficiency, as compared to prior wireless generations.

The higher density offered by 5G means that it has the ability to support 10x more connected devices, per square kilometer of network, as compared to 4G LTE. This feature is particularly relevant to the proliferation of the Internet of Things (IoT) because a 5G network enables the simultaneous operation of 1 million connected devices in one square kilometer. In a smart city, 5G and IoT become essential for applications such as traffic management, emergency response, and self-driving cars.

READ MORE: What’s the Difference Between 4G LTE and 5G?

Wireless Sensor Network (WSN)

A wireless sensor network (WSN) is a network that is untethered to any wires and comprises a large number of small, low-power devices called sensor nodes. Specifically, these nodes are equipped with sensors, microcontrollers, and wireless communication capabilities, and are deployed in a variety of environments to monitor and collect data.

In a smart city, a WSN can be used to monitor temperature, humidity, and air quality in a building.

READ MORE: Internet of Things (IoT) Sensors and Actuators


DASH7 is a long-range, low-power wireless communications standard, ideally suited for sensor networks, active RFID tags, and other Internet of Things (IoT) devices. This standard is typically used in applications requiring modest bandwidth like text messages, sensor readings, asset tracking, or location-based advertising coordinates. More specifically, these use cases are applied to material monitoring, warehouse optimization, and smart meter developments.


Addressing refers to the process of uniquely identifying and addressing IoT devices and other network entities. This is necessary to ensure that data and commands can be properly routed and delivered to the correct devices and systems in a smart city.

IoT Applications for Smart Cities

Smart city services and Internet of Things (IoT) applications are improving the way we live. Examples range from greater safety on roads, to saving valuable time from daily commutes, to providing cleaner air for people to breathe – their impact has already been felt in cities around the globe. Major IoT applications for smart cities are smart urban mobility, urban sustainability, and smart buildings & environment.

1) Smart Urban Mobility

Traffic congestion is one of the key challenges of every city administration. IoT is playing a key role in alleviating traffic congestion by making various types of real-time data available on vehicular movement.

Traffic Monitoring

Smart traffic management solutions are being used to monitor and analyze traffic flows. These systems optimize traffic lights and help prevent roadways from becoming too congested, based on time of day or ‘rush hour’ schedules.

According to CTIA’s Smart Cities Playbook, smart traffic management systems have the potential to reduce congestion by 40% and save $100 million annually.

Smart Parking

Smart parking applications use cameras and other sensors to help drivers find available parking spaces without continuously circling around crowded city blocks or parking lots. Sensors placed on parking spots transmit data to a server, which delivers information to drivers via mobile phone applications or display boards. To-date, smart parking has already increased the capacity of roads by 10%.

Connected Vehicles

Connected cars and transport services are growing in adoption, with their ability to provide real-time traffic data and faster routes to drivers. According to Insider Intelligence, connected cars will make up 97% of the total number of registered vehicles in the U.S. by 2035.

2) Urban Sustainability

Our world is transitioning to more environmentally-aware smart cities and IoT technologies are the catalyst for this shift. Beyond existing initiatives – such as switching to energy-efficient LED lighting or creating low-emission zones – smart lighting, smart meters, and smart waste management are important examples of urban sustainability.

Smart Lighting

Smart lighting changes the intensity of street lights based on movement of vehicles and pedestrians. This results in notable energy savings and reduction of light pollution. Also, installing sensors to detect malfunctioning public lights reduces maintenance costs.

According to CTIA’s Smart Cities Playbook, smart lighting solutions have the potential to save more than $1 billion per year across the United States. While in Europe, on a more micro-level in the city of Guadalajara, Spain, 13,500 LED lights were connected to a central management system, reducing street lighting energy consumption by 68%.

Smart Meters

Smart meters are IoT devices that are attached to buildings and connected to a smart energy grid, allowing utility companies to manage energy flow more effectively. Also, smart meters enable users to track their power consumption, leading to more energy usage awareness and potential savings. Insider Intelligence predicts that utility companies will save $157 billion by 2035 due to smart meter adoption.

As an example, Vodafone, one of the world’s largest wireless carriers, has over 12 million smart meter connections globally using its IoT technology, saving an estimated 1.6 million tons of CO2e.

Smart Waste Management

Smart waste management can improve efficiency and reduce costs by using capacity sensors to track the level of waste held in garbage cans and recycling containers, determining the most efficient pick-up routes for waste management companies or public services.

3) Smart Buildings and Environment

One of the key purposes of a smart city is to improve the quality of life of its citizens in both indoor and outdoor environments. Internet of Things (IoT) technologies and data are advancing a wide range of urban services, buildings, and infrastructure in order to achieve this purpose.

In particular, smart buildings use a number of IoT devices to support these goals, including the following hardware:

Smart Building Hardware Examples for Smart City
Source: Vodafone.

Smart city and Internet of Things (IoT) technology are also working in tandem to solve problems in air quality, building automation, and noise.

Air Quality Monitoring

Air quality data is being used in cities around the world to support urban planning decisions, such as where to locate new buildings and roads, and to develop and enforce air pollution regulations. Specifically, air quality monitoring has been made possible with optical, electrochemical, and beta attenuation sensors placed around a smart city.

Building Automation

IoT technologies are helping to improve the efficiency, safety, and comfort of public buildings such as schools, libraries, government facilities, and community centers through automation. The goal with building automation is to enhance the end user’s experience and reduce operating costs, all while providing a more sustainable environment.

Noise Monitoring

Different types of sensors and devices can be used for noise monitoring, such as microphones, accelerometers, and geophones. These IoT devices are placed strategically around a smart city to capture data on noise levels, which is then transmitted to a central monitoring system.

Data from IoT devices allow smart city officials to identify hotspots of noise pollution and bring interventions such as sound barriers, green spaces, and noise-reduction building materials.

Adam Simmons covers Towers for Dgtl Infra, including American Tower (NYSE: AMT), Crown Castle (NYSE: CCI), SBA Communications (NASDAQ: SBAC), Cellnex Telecom (BME: CLNX), Vantage Towers (ETR: VTWR), IHS Holding (NYSE: IHS), and many more. Within Towers, Adam focuses on the sub-sectors of ground-based cell towers, rooftop sites, broadcast / radio towers, and 5G. Adam has over 7 years of experience in research and writing for Towers.


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