At Home in Two Worlds: Network and IT from a Single Source
Interview with Thomas Dettenberg, Managing Director of GELSEN-NET Kommunikationsgesellschaft mbH
Today, when talking about digitalization, it involves more than fast internet: it's about security, competence, and structure. This is exactly where the strength of GELSEN-NET Kommunikationsgesellschaft in Gelsenkirchen lies. The company is one of the leading regional providers of fiber optics, IT services, and digital infrastructure. With its own network, modern data centers, and a focus on security, GELSEN-NET supports municipalities, businesses, and private households into the connected future. Thomas Dettenberg, a member of the three-person executive management, emphasizes that GELSEN-NET is more than just a telecommunications provider, and explains how technological strength develops from regional roots.
When GELSEN-NET was founded in 1983, cable television was the new future topic. However, the real success story began with the liberalization of the telecommunications market in 1998. The company transformed from a municipal utility project into a modern telecommunications provider and finally into a full-service IT systems house. Today, GELSEN-NET operates a fiber optic network over 1,000 km long and serves more than 40,000 residential units as well as numerous business customers in eight cities in the Ruhr area. Approximately 130 employees generated a turnover of 26.1 million EUR in 2024.
Security through own network
A central competitive advantage of GELSEN-NET is its own fiber optic network, which enables security and control from a single source. "Our network is significantly safer than being on the move in foreign structures," emphasizes Thomas Dettenberg. This independence is crucial especially for customers from sensitive areas. The company follows the Zero Trust principle – trust no one – and combines technical security with education. Regular training and a risk check certified by the BSI help medium-sized businesses to detect vulnerabilities early. "We help stabilize systems before damage occurs," says the managing director. The core of GELSEN-NET's security philosophy is consultancy before product sales.
Digital Sovereignty
Even in data management, GELSEN-NET takes its own path. The company-owned open cloud platform is operated exclusively in data centers in the Ruhr area and meets the highest data protection requirements. "We do not believe in a single solution," says Thomas Dettenberg. "Eggs belong in several baskets: Hyperscalers where it makes sense, and sensitive data in a regional cloud." Thus, the company actively contributes to the digital sovereignty of its customers, independent of non-European legal risks.
People and Values
Behind the technical success is a strong team. Many specialists have been trained in-house and have been part of the company for years. "It's not the technology, but the people that make the difference," emphasizes Thomas Dettenberg. This attitude shapes the corporate culture: down-to-earth, solution-oriented, and regionally anchored. Since 2023, GELSEN-NET has been majority owned by GELSENWASSER AG, with Stadtwerke Gelsenkirchen holding 49%. The new headquarters in the Gelsenwasser district symbolizes cooperation and future orientation. For the coming years, GELSEN-NET has clear goals: further expansion of the fiber optic infrastructure, strengthening IT security services, and consistent development of regional cloud offers. "We are investing and growing step by step," summarizes the managing director. "Our goal is to sustainably secure the digital capability of the Ruhr area – with technology that works and people who are accessible."