Ninett Rosenfeld and Julia Zimmermann

In 2019, Berlin-Köpenick experienced a 30-hour power outage. The blackout took the city by surprise. The police drove through the streets with signs and made loudspeaker announcements to inform residents and prevent a mass rush to the emergency stations. The idea for Kiezbox 2.0 was born. From February 2023 to September 2025, the project was developed and implemented as a pilot measure as part of the Smart Cities model projects (MPSC) programme and the "Digital Together:Berlin" (GD:B) smart city strategy. Kiezbox 2.0 aims to strengthen the resilience of the city of Berlin in the event of a power failure. In an interview, Ninett Rosenfeld and Julia Zimmermann from the Berlin Technology Foundation (Technologiestiftung Berlin, TSB) explain exactly what Kiezbox is and how it works in a crisis.

What can Kiezbox 2.0 do?

Roughly speaking, if the mobile network fails and the emergency services cannot be reached in an emergency, the Kiezbox can be used to call help.

How exactly does it work?

Essentially, it is a solar-powered system consisting of multiple Kiezboxes distributed across flat roofs throughout the city. In the event of a blackout, these boxes create a Wi-Fi mesh network that can operate for up to five days without power.

How can the Kiezbox, as a GD:B project, strengthen Berlin's resilience? 

"How do we know where help is needed if no one can call?" Kiezbox 2.0 addresses this question and therefore supports Berlin's emergency services. Using the Kiezbox Wi-Fi, the people can call the Berlin fire department directly via voice over IP and communicate in real time despite power failures. This serves to maintain the existing emergency communications and the city can continue to function in the event of a crisis. This is made possible by a streamlined app installed on every box: the Kiezbox information portal. In addition to emergency calls, the portal provides official information from the Federal Office for Civil Protection and Disaster Assistance. This enables citizens to help themselves individually and independently. The information portal also provides vital information about locations throughout the city where the population can find necessary resources such as water, defibrillators or even toilets in the event of a crisis.

The Kiezbox also uses sensors to measure environmental data. Who analyses this data and for what purpose?

Any desired number of sensor boxes can be installed in each Kiezbox. We measure temperature, humidity, particulate matter pollution and noise level data. This is transmitted to a database every five minutes using the LoRa protocol. The information is then visualised using the open-source software Grafana. As the sensor module has a flexible range of applications and the sensors are individually interchangeable, the data can be analysed in a variety of different ways. For example, it can be used to highlight trends or differences in the microclimate. However, we do not currently use the data.

The Kiezbox pilot phase took place in the Schöneberg district. Why there in particular?

TSB is based at Bayerischer Platz – and thus in Schöneberg. Given that we set up the pilot and the mesh network ourselves, we chose Schöneberg as the pilot area. This had the advantage that we were able to work flexibly on the Kiezbox during the test phase and make changes and improvements to the systems nearby. Schöneberg Town Hall is also one of 44 disaster control beacons in the city of Berlin.

Who did you collaborate with?

TSB is the sole project manager and was therefore responsible for implementing Kiezbox 2.0. However, without constant communication with the administration and the Berlin fire department, the project would not have been so successful. We collaborated with the Berlin fire department and the Competence Centre for Civil Protection and Crisis Management of the Senate Department for the Interior and Sport to define the requirements. In addition, we also worked with the Berlin fire department to develop the technical and organisational requirements for a communication system like this – As considered from the perspective of both the population and the emergency services. These requirements were confirmed in discussions with the Berlin Police. We established additional contacts with the operators of the official emergency app of the federal states (nora) and with employees at the disaster control department in Tempelhof-Schöneberg, for example. Economic players also showed an interest.

Was there a crisis exercise with the Berlin fire department in mid-June 2025? What was tested during this exercise? 

In preparation for the crisis exercise, we tested the entire system thoroughly. First, we carried out technical tests to ensure that the Kiezbox could transmit calls to the Berlin fire department's control centre via voice over IP with good voice quality and only minimal delay. During the crisis exercise itself, the acceptance of the system was then tested. Specifically, this meant that we ran through the emergency procedure during a widespread power outage with people who had not used the Kiezbox emergency call system before. We then asked them how they found using the information portal and making an emergency call. We also tested whether the call takers at the Berlin Fire department control centre were able to receive emergency calls, record and process the respective emergency as usual.

What insights did you gain from the crisis exercise?

We were able to demonstrate that the Kiezbox emergency call system works well. The test subjects were able to make an emergency call via the system and the call takers were able to receive, understand and process the call. The information portal also allowed the test persons to find important information. This helped them to deal with the crisis situation independently. However, we also discovered that information about hospital locations and collection points, for example, was missing and that we could expand the app with additional open data. It also became clear that a direct connection between the Kiezbox system and a fire station would significantly increase the robustness of the system.

The Kiezbox 2.0 pilot project ended in July 2025. What does the future hold for Kiezbox? Are there already plans in place?

We are currently working on a draft that focuses on the medium-term consolidation and actual use of Kiezbox in Berlin. The Berlin fire department and police would support the project with a letter of intent. The draft has been submitted to the Senate Department for the Interior and Sport for review.

What does the city of the future look like for you?

Inclusive and citizen-oriented. A city where technology is used as a means to an end – and not the other way around.

Please complete the following sentence: "Berlin is smart because ..."

... off-the-shelf solutions have never worked here.