Yettel is phasing out outdated 3G technology and doubling or tripling 4G capacity while rolling out 5G in the project worth "tens of billions of forints", Koller said. All of the more than 4,000 Yettel base stations are being upgraded, he added.

The latest 5G technology is available at over 700 Yettel base stations, while 5G now accounts for about 15% of mobile internet turnover, he said. By year-end, the number of 5G base stations will reach 1,000, he added.

Yettel is owned by Czechia's PPF Telecom Group.