AIS and True Corp each won a 1,800MHz licence in the November auction, while True and Jasmine International each secured a 900MHz licence in the ensuing NBTC auction last month.
Total Access Communication (DTAC) has already launched 4G on 1,800MHz, under a CAT Telecom concession.
As AIS failed to win a 900MHz licence, it is rushing to migrate its 12 million 2G customers on 900MHz to AWN by offering them subsidised handsets