True Move and Digital Phone Co (DPC) will be required to oversee their existing second-generation (2G) customers for another six months after the July 17 deadline to ensure service continuity to consumers, says the National Broadcasting and Telecommunications Commission (NBTC).
The two mobile operators have to transfer all existing 2G customers to other networks before the licences from the first 4G spectrum auction are issued, scheduled for next January, said NBTC secretary-general Takorn Tantasit.
"We have to extend the deadline for a second time as we don't want signals for 2G SIM cards on the two mobile networks cut off after July 17," he said.
The concessions of True Move and DPC from owner CAT Telecom expired on Sept 15, 2013. The NBTC forced the two companies to retain their customers until July 17 last year after their concessions expired.
The commission then extended the period another year after the military government ordered the NBTC to suspend 4G spectrum auctions until this year.
True Move has 700,000 customers on the 1800-megahertz spectrum, down from 7 million last year and 17 million in October 2013.
DPC, a unit of mobile leader Advanced Info Service (AIS), has about 1,000 users in its network.
"The NBTC will propose the extension to the National Council for Peace and Order this week for approval," said Mr Takorn.
True Move and DPC must return mobile call credits to customers before the signal is cut off. Up to 20 million baht of calling credits are left over on their prepaid mobile systems.
NBTC plans to auction 25 MHz of bandwidth on the 1800-MHz spectrum in November, with two licences each containing 12.5 MHz. The spectrum was previously used by True Move and DPC.
"If the 4G licences have already been awarded, signals for 2G SIM cards on the two mobile networks will be cut off immediately," he said.
Mr Takorn said the NBTC is drafting a regulation to oversee 2G customers on the 900-MHz spectrum operated by AIS, whose concession with owner TOT Plc is due to expire in September.
AIS has 42 million subscribers, 39 million of whom are on the 2100-MHz spectrum network under the licence regime.
"The regulation is projected to become effective in August. The oversight period would be from September to April next year," he said.
Another auction for 20 MHz of bandwidth on the 900-MHz spectrum is scheduled for December. The NBTC expects to award these licences by next March.