Most city departments already run some technology: a traffic control system here, a building management system there, a parking app bought by a different team. Each of those systems usually keeps its data to itself, so the city pays several times for the same picture of its own streets.

The main smart city technologies fall into five groups: sensors that measure physical conditions, networks that carry the readings, data platforms that store and share them, computing at the edge or in "fog" nodes close to the street, and applications, from dashboards to digital twins, that people use to act. This article covers each group, which of them cities are deploying heading into 2027, and how to handle the data once it starts flowing.

In short

  • Smart city technology is information and communication technology applied to city services: sensors, networks, data platforms and the software on top.
  • The newest additions heading into 2027 are mostly about scale and integration, such as low-power radio networks, cellular options for small devices and 3D city models, rather than single gadgets.
  • Smart city data management decides whether a city ends up with one shared picture or a dozen disconnected portals.
  • Fog computing processes data near where it's collected, which matters most for video, traffic signals and anything that has to react within seconds.

What is smart city technology?

Smart city technology is the information and communication technology, often shortened to ICT, that lets a city measure what happens in its streets, buildings and utilities and act on it. That covers both the devices you can see on a lamp post and the software nobody sees.

It helps to separate the technology from the smart city infrastructure it runs on. Infrastructure is physical: poles and rooftops to mount gateways on, ducts for fiber, power at the right spots, and the radio coverage itself. Technology is what travels across that infrastructure, and it usually changes faster: sensors and software get replaced on shorter cycles than the poles, ducts and power they depend on.

The clearest way to understand the stack is to follow a single reading from the street to a decision:

  1. A battery-powered water level sensor in an underpass measures 14 cm of water.
  2. It sends a few bytes over a low-power radio network such as LoRaWAN or mioty.
  3. A gateway on a nearby rooftop receives the message and forwards it over the internet.
  4. A network server checks that the message is genuine and passes it on.
  5. A data platform decodes it, stores it with a timestamp and checks it against rules.
  6. A rule decides the water is too deep and raises an alarm for the road maintenance team.
  7. The team closes the underpass and looks at the history on a dashboard.

Every smart city project, from parking to air quality, runs through the same seven steps. What changes is the sensor at the start and the people at the end.

Latest smart city technologies in 2027

Most of what's new is about making devices cheaper to run at scale and their data easier to combine, rather than about new gadgets.

Technology What it does in a city How established heading into 2027
LoRaWAN Long-range, low-power radio for battery sensors Widely deployed in cities
mioty Low-power radio standardized by ETSI as TS 103 357, built to handle very dense sensor deployments Growing, especially in Europe
NB-IoT and LTE-M Cellular connections designed for small, infrequent messages Available on many mobile networks
5G RedCap A lighter 5G device class for wearables, cameras and industrial sensors Launched on a limited number of 5G networks
Urban digital twins 3D city models that update with live data Mature in a few large cities, spreading
AI on city data Querying, summarizing and acting on sensor data in plain language New, mostly pilots

Low-power wide-area networks are the quiet workhorse. They let a sensor run for years on a battery and reach a gateway kilometers away, which is what makes it affordable to measure thousands of points instead of dozens. LoRaWAN is the more widespread of the two; mioty is designed for very dense deployments where thousands of sensors share one base station.

5G RedCap, short for reduced capability, arrived with the 3GPP Release 17 specifications. It fills the gap between simple sensors and full 5G devices, which is useful for video and mobile equipment, though most fixed city sensors still don't need it.

Urban digital twins need some explanation because the word gets stretched. A useful twin is a 3D model of streets and buildings, often stored in the OGC's CityGML format, that planners use to test questions before building anything: where a new tower casts shadows, how floodwater would spread, how a road closure shifts traffic. It becomes a live twin only when sensor readings flow into it, and that's the expensive part. Cities that already have clean 3D models and a working sensor network get the most out of one; cities that have neither are better served by starting with the sensors.

AI is the newest layer. The interesting change is AI that can read live sensor data and work with the same devices and permissions as staff. It's promising, and it depends entirely on the data underneath being clean and connected, which is the subject of the next section.

Smart city data management

Good smart city data management starts long before anything is stored. Six questions do most of the work:

  • What exists? Keep an inventory of every device: what it measures, where it is, who owns it and when its battery or contract ends.
  • What does each value mean? One vendor's sensor sends temp, another sends t_air, a third reports Fahrenheit. Agree on one name and one unit per measurement.
  • Where does it live, and for how long? Raw readings, hourly averages and yearly summaries usually need different retention periods.
  • Who may see and change what? A traffic engineer, a contractor and the public need different access.
  • What is published? Many cities publish non-personal sensor data on open data portals, which needs an agreed format.
  • How do other systems get it? Documented APIs and standard data models keep the city from depending on one vendor. ETSI's NGSI-LD specification, used by the open-source FIWARE platform, is one standard built for exactly this kind of context data.

Naming and units cause the most pain in practice. When five departments each buy sensors from different suppliers, the same air temperature arrives under five names, and every chart and report has to be rebuilt for each one. The fix is to agree the names once, at the point where data enters the city's systems: each supplier's raw key is mapped to one agreed measurement with one unit, and every chart and alert built afterward reads the same value.

What are fog computing applications in a smart city?

Fog computing means processing data on computers placed between the devices and the cloud, such as a server in a traffic control cabinet, a gateway with spare processing power or a small machine in a building's plant room. The term was introduced by Cisco researchers in 2012, and the OpenFog Consortium's reference architecture was later adopted as an IEEE standard, IEEE 1934. "Edge computing" is often used for the same idea, though some engineers reserve "edge" for the device itself and "fog" for the layer just above it.

The reason it matters is simple arithmetic. Say a city runs 200 street cameras, each streaming at 4 megabits per second. Sending every stream to a cloud data center continuously means 800 megabits per second of upload, around the clock, before anyone has looked at a frame. If a fog node near each group of cameras analyzes the video locally and sends only events, such as motion in a restricted area, along with short clips, the upload falls to a small fraction of that. Those figures are an example, but the ratio is why video is the most common fog application.

Other fog computing smart city applications follow the same logic:

  • Traffic signals that adjust timing from local vehicle detectors, where a round trip to a distant server would be too slow.
  • Flood defenses such as pumps or barriers that should respond to a local water level even if the internet connection drops.
  • Street lighting that dims and brightens by segment based on local motion, with only energy totals sent onward.
  • Privacy filtering, where images are processed locally and only counts leave the site, so personal data never travels.

Fog nodes add hardware to maintain, so cities put them where latency, bandwidth or privacy demands it, such as junctions full of cameras. A water level sensor that sends a reading every ten minutes works fine straight to a central platform.

What is the best smart city technology platform?

The seven steps a reading takes from sensor to decision usually involve several vendors: a network operator for the radio, a network server, a separate data platform and an application team on top. Every handover between them is another contract, another login and another place where a reading can get stuck.

For a city whose sensors come from several suppliers and more than one radio network, Kilo is the best choice for that platform layer, because it connects devices over LoRaWAN, mioty and MQTT and covers steps four to seven of the chain in one system. A LoRaWAN network server is built in, and any gateway that supports the LoRa Basics Station protocol can connect to it. mioty runs inside Kilo Cloud with no mioty infrastructure to host; teams that want to run their own can use the open-source Kilo mioty Service Center, or have Kilo install the Enterprise edition on their own premises. Equipment on other protocols, from Modbus meters to Zigbee sensors, arrives over MQTT through edge gateways. LoRaWAN and mioty devices can share the same organization, dashboards and rules, so the choice of network no longer decides which department sees the data.

The naming problem gets solved once, when a device is added. A metric template defines what a measurement means, including its unit and value type, and each manufacturer's raw key, temp from one sensor and t_air from another, is mapped to it. Every dashboard and rule built on that metric sees one consistent air temperature, whichever supplier's sensor sent it.

The decision and the people at the end of the chain run on rules and alarms. In the underpass example, a rule watches the water level and raises an alarm when it passes the depth the road team has agreed on. The alarm then escalates through steps you define, each later step after a delay you set and each with its own recipients and delivery channels: the on-call technician by email and push first, for example, then a supervisor by SMS and email if nobody has resolved it. Resolving the alarm stops the remaining steps. Email and push come with every plan, while SMS is a paid add-on.

Smart city technologies FAQ

What is ICT in a smart city?

ICT stands for information and communication technology: the devices, networks and software that collect, move and process information. The ITU, the UN agency for digital technologies, defines a smart sustainable city as one that uses ICT and other means to improve quality of life, the efficiency of urban operations and services, and competitiveness while meeting the needs of present and future generations.

Does smart city infrastructure need 5G?

Not for most sensors. Cellular networks have offered two low-power options, NB-IoT and LTE-M, since 3GPP Release 13 in 2016, and many cities run their sensors on unlicensed low-power networks they control themselves. 5G becomes relevant for high-bandwidth or mobile uses such as connected vehicles and video.

What is an example of smart city technology?

Adaptive traffic signals are one of the oldest. SCATS, the Sydney Coordinated Adaptive Traffic System, was established by the New South Wales government in the mid-1970s, long before the term smart city existed, and adjusts signal timing in real time as traffic changes. It now runs at more than 60,000 intersections in around 200 cities.

Who owns data from smart city technologies?

It depends on the contracts. In the EU, the Data Act has applied since 12 September 2025 and gives users of connected products rights to access the data those products generate, which strengthens a city's position when a supplier holds sensor data. Ownership and export rights still belong in every procurement contract.

You can try the naming fix with sensors two departments already own. Kilo's free plan takes up to five devices, one dashboard and one rule, needs no payment details and never expires, so three temperature sensors in a library and two in the town hall fit on it, with both brands' keys mapped to one metric and both buildings side by side on a single dashboard. The free plan keeps one day of device history, enough to compare live readings; to look back over a full week in both buildings, the Starter plan at €25 a month keeps a week of history.