
There were 121.53 million mobile phone SIM cards used last year, of which 53.05 million numbers belonged to Advanced Info Service, 36.05 million to True Corp, 30 million to Total Access Communication, 2.32 million to CAT Telecom, and 0.11 million to TOT.
The huge jump was a result of the availability of more spectrum bandwidth to cellular operators, including the auction of 2.1GHz in 2012, and 1800MHz and 900MHz in 2015 to 2016, which enabled them to expand the wireless broadband service.