DNA is introducing download speeds of up to 1GBps in the cities of Helsinki, Tampere and Turku in its latest stage of network improvement ahead of 5G.
Work has already started in Helsinki, with Tampere and Turku to follow in the coming weeks.
DNA said it was planning to concentrate in the busiest areas of each city for data usage and speeds will double those previously available. It said it will use a combination of new, unnamed network technologies and fresh frequency bands.
Helsinki's network upgrade will stretch from the city centre to the eastern outskirts, while Tampere and Turku will see its municipal borders strengthened.
Jarkko Laari, Director, Radio Networks at DNA, said: "Mobile data usage is constantly growing, and DNA’s customers are the most enthusiastic data users in the world. By continuously developing our mobile network, we ensure that our customers are able to use our network smoothly in all activities also in the future."
The operator, which launched its network upgrade program last year, said LTE will continue to underpin its network event after the introduction of 5G. Laari added: "Initially, 5G will be a more localised technology that facilitates high-quality telecommunication services in areas and applications where optical fibre connections are unavailable or prohibitively expensive."
It is planning to introduce 5G once the relevant licence comes into play on 1 January next year. DNA paid €21 million for a 3.67-3.8GHz frequency band in the country's spectrum auction earlier this month.