Smart Home

In a normal home, every device works on its own. The lamp knows the light switch, and nothing else. The heating doesn’t know whether anyone is home. In a smart home, by contrast, these devices are connected to a shared network, meaning they are technically linked to one another. As a result, they can exchange information and respond to commands from outside. You control them via an app on your phone, via spoken sentences, or via fixed rules set up in advance. Typical examples are lamps, heating thermostats, roller shutters, power outlets, door locks, and surveillance cameras.

From toy to billion-dollar market

For a long time, the connected home was seen as an expensive gadget for tech enthusiasts. That has changed because the components have become cheap. A radio chip that connects a lamp to the network today costs only a few euros. The market is correspondingly large: several hundred million such devices are sold worldwide every year.

For the big tech companies, this is about more than just selling lamps. Whoever controls the system through which all devices run controls access to the living room. Amazon, Google, and Apple have therefore been competing for this role for years. A user who has set up twenty devices in one system rarely switches provider.

There’s also a practical reason: energy. Heating that automatically turns down when no one is home saves measurable amounts of money. In Germany, programs therefore subsidize the installation of smart thermostats. Smart electricity meters that report consumption down to the minute also fall into this category.

Sensors, radio, and the hub

A smart home consists of three types of components. Sensors measure something: temperature, brightness, motion, whether a window is open. Actuators do something: switch, dim, open, lock. And a control hub connects the two and decides what happens when.

The connection usually runs via radio, often over Wi-Fi or via more energy-efficient wireless standards such as Zigbee and Matter. These standards are more important than they sound. In the past, every manufacturer spoke its own language, and a lamp from company A didn’t understand the hub from company B. Matter is the industry’s attempt to agree on a common language.

The actual intelligence lies in the rules. A typical rule reads: if the motion sensor in the hallway triggers after sunset, switch the light to thirty percent. Such if-then chains are called automations. Some systems additionally learn from the residents' behavior, for instance when heating is usually turned on. A common misconception is that artificial intelligence lies behind every smart home. Most of it consists of simple, fixed, pre-programmed rules.

Voice assistants, data protection, and cloud outages

Most people encounter the topic through voice assistants like Alexa, Google Assistant, or Siri. For many, they are the entry point, because a single sentence is enough to switch several devices. Robot vacuum cleaners, smart doorbells with cameras, and connected heat pumps also fall under the term.

In the news, the topic often appears with a critical tone. A microphone in the living room and a camera at the front door generate data that frequently ends up on the manufacturer’s servers, that is, in the so-called cloud. Whoever has access to this data knows a great deal about the residents' daily lives. Security researchers also regularly show how poorly secured cameras can be accessed from outside.

A second recurring problem is dependency on the manufacturer. If a company shuts down its server service, an expensive lamp quickly turns into an ordinary light bulb. This has happened more than once. That’s why some users rely on systems that run entirely within their own home and function without an internet connection.