5G, which went into operation in 81 provincial centers, especially Istanbul, Ankara and Izmir, on April 1, 2026, will be gradually expanded throughout the country in the next two years. However, this new technology, which operates in high frequency bands, suffers from signal loss due to thick walls, glass facades and reinforced concrete structures, making indoor solutions stand out in heavily used indoor areas such as hospitals, shopping malls, stadiums and airports. It is pointed out that after the rapid completion of open space coverage in city centers, the real engineering exam will be held indoors. Telecommunications engineer Bahar Öztürk, who planned and managed more than 250 indoor communication projects across Türkiye, evaluated the spread of 5G throughout the country in terms of indoor coverage.
Öztürk states that the speed advantage provided by the high frequency bands used in 5G in open areas is significantly weakened when entering closed spaces. For this reason, he says that the deployment of passive and active indoor distributed antenna systems in crowded indoor areas such as metro stations, hospitals, stadiums and production facilities is decisive for the speed and low latency performance promised by 5G to truly reach the user.
Öztürk, who has been involved in the planning and commissioning of in-building mobile communication solutions in national-scale public transportation and public infrastructure projects such as Istanbul Airport, Gayrettepe-Istanbul Airport Metro Line and High Speed Train in his 18 years of professional experience, underlines that field tests and signal measurements should be repeated at regular intervals after the project is completed. He emphasizes that accurate engineering planning at an early stage in indoor projects prevents costly revisions that may arise in the future.
Stating that the shared infrastructure model between operators stands out in terms of cost and site access in the commissioning of new generation networks, Öztürk states that this model, in which a single in-building system can serve multiple operators at the same time, shortens both investment and installation time, especially in large closed areas such as stadiums and hospitals.
Öztürk, who carries out the reporting and resource planning processes of network investments exceeding 400 million dollars annually, emphasizes that the transition to 5G will be measured not only by outdoor coverage, but also by the performance in indoor spaces where people spend most of the day. Reminding that supplier and contractor coordination is a determining factor in the project schedule, Öztürk states that having different stakeholders act on the same schedule in indoor projects reduces time loss in the field. Experts predict that indoor 5G transformation will accelerate in the coming period, especially in densely populated cities and public transportation lines.