DTAC will invest more than 70 billion baht over the next three years to develop its 4G wireless network.
The company, which recently failed to secure its own 4G spectrum license, plans to use part of the funds set aside for the spectrum bidding to expand its 4G coverage nationwide, improve quality and heavily market its 4G services.
DTAC, which is owned by Norwegian telecoms giant Telenor, is the second largest telecoms operator in Thailand with 25.3 million subscribers.
DTAC currently has 2.3 million customers subscribing to 4G, with the company aiming double this number by the end of the year.
As part of its 70 billion baht investment in 4G, the company plans to increase the bandwidth on the 1800 MHz to 20 MHz, which will mean it can open up its services to a wider range of 4G enabled devices.
By the end of next quarter, it will roll out 4G coverage to 77 provinces, which by the end of 2018 will offer 4G speeds of 150Mbps, the company has said.
A new promotional campaign will aimed to get its 3 million 2G customers to upgrade to either 3G or 4G services, with the company offering free and heavily discounted 4G enabled smartphones to try and persuade people to make the switch.
DTAC already offers some of the most affordable 4G tariffs in Thailand, with prices starting from 299 Baht for 1.5GB of 4G use and 100 minutes of talk time.
In November, DTAC missed out on securing a license in the 4G spectrum auction, with nearest rivals AIS and True securing the 1800 MHz licenses, while True and newcomer Jasmine International secured licenses for the 900 MHz network.