Total Access Communication Plc (DTAC) has set aside a three-year investment budget of 70 billion baht for an aggressive nationwide expansion of its fourth-generation (4G) wireless network.
The development by the country's second-largest mobile operator can be seen as a psychological drive to boost consumer confidence in its network quality after the company failed to secure a 4G licence.
DTAC is also on the verge of increasing 4G bandwidth by an additional five megahertz to 20MHz on its existing 1800MHz spectrum for 4G service.
The bandwidth increase will make DTAC the only mobile operator providing 4G service on 20MHz on one spectrum.
True Move won two licences to provide 4G service on 15MHz of bandwidth on the 1800MHz spectrum and another 10MHz on the 900MHz spectrum.
Advanced Info Service Plc (AIS) won a licence to provide 4G service on 10MHz of the 1800MHz spectrum.
"Providing 4G service on a single spectrum can accommodate a wider range of 4G mobile capabilities and handset prices, ranging from low-end to high-end models," DTAC chief executive Lars Norling said.
"This will extend greater options to customers and provide faster 4G speeds of up to 150 Mbps, up from 120 Mbps."
He said the upgrade would differentiate DTAC's service from 4G service available on other spectra.
The company will spend 20 billion baht this year on 4G network expansion, Mr Norling said.
The remaining 50 billion baht will be used over the next two years for 4G network investment and marketing activities.
"Our 4G base stations will increase to 6,000 covering all 77 provinces nationwide by June, up from 2,200 stations covering 46 provinces," he said.
"We expect the number of our 4G subscribers to increase to 4.5 million this year from 2.5 million."
Chief technology officer Prathet Tankuranun said DTAC would have only 5MHz of bandwidth serving 2G customers, with the remaining 20MHz accommodating 4G service.
He said rivals AIS and True Move must use carrier aggregation technology to combine bandwidth from different spectra to provide 4G LTE Advanced.
LTE Advanced provides optimum mobile connection speed only to expensive 4G devices, not most of the smartphones available in the market, Mr Prathet said.
"DTAC will be able to provide 4G service to the mass market," he said.
Mr Prathet said DTAC would spend 2 billion baht over the next three months on a promotion aimed at persuading its 3 million 2G customers to migrate to its 3G and 4G networks.
DTAC is offering 4G tariff packages that are the lowest rates in the local mobile market, he said.
The company's monthly 4G tariff plans start from 299 baht for 1.5 gigabytes of 3G/4G internet use and 100 minutes of calls, increasing to 1,999 baht for 80GB and 2,000 minutes of calls.