The National Broadcasting and Telecommunications Commission (NBTC) will prioritise digital radio next year after this month's digital-TV auction.
The NBTC's master plan stipulates the broadcasting regulator must begin a process of digital transition for radio within four years of its establishment.
Col Natee Sukonrat, chairman of the NBTC's broadcasting committee, said trials for digital radio will start early next year with collaboration from government agencies that own radio frequencies.
It will use unallocated frequencies in the VHF band for trials.
In March, the NBTC conducted a trial with the DAB+ standard to test-run equipment and an aerial service.
Col Natee said the NBTC also appointed the International Telecommunication Union as its adviser for the digital radio transformation including the digital radio standard and technical issues.
Its initial concept will be in line with digital TV, which will be divided for public, commercial and community purposes.
Although radio is declining in popularity in terms of media spending and audiences, particularly teenagers, online radio is on the rise.
However, another factor in radio's revival is to make it portable via mobile devices, allowing a variety of people to listen to radio without charge.
For online radio, listeners must pay data usage fees to telecom operators.
"Broadcast service will be provided mostly for free. Telecommunications service is actually a pay service for data usage. The two have different concepts for frequency use," Col Natee said.
The NBTC has also discussed the digital radio transition with car makers.
"I believe radio will not disappear easily from Thailand, as people in rural areas still listen to it for information. Moreover, radio may revive its popularity with higher quality, easier accessibility and mobility," Col Natee said.
Of the country's 525 radio stations, 133 are owned by private companies and civil organisations and 392 by government agencies _ the Royal Thai Army, MCOT Plc, the Royal Thai Police and the Public Relations Department.
They must return their frequencies in 2017 before radio broadcasting concessions switch to a licensing regime.
For community radio, the NBTC has accepted applications for almost two years, and 3,333 stations have been registered.