The telecom regulator is concerned the planned fourth-generation (4G) auctions may be delayed if CAT Telecom's labour union disagrees with the agency's proposal of returning an unused five megahertz on the 1800-MHz spectrum to the regulator to add spectrum bandwidth for auction.
CAT Telecom must make its labour union understand that bandwidth has to be returned without any conditions attached or compensation from the government, said Takorn Tantasith, secretary-general of the National Broadcasting and Telecommunications Commission (NBTC).
He said the NBTC did not have the authority to pay any compensation to state agencies returning a portion of a spectrum before the expiry of a concession.
The original plan for the 4G auction on the 1800-MHz spectrum was to auction two licences of 25 MHz of bandwidth in November, each licence of 12.5 MHz.
The 25 MHz of bandwidth is from True Move and Digital Phone Co, whose concessions with CAT Telecom expired in 2013.
The NBTC has ordered both mobile operators to continue service and to look after their 2G users until next January.
CAT and Total Access Communication Plc (DTAC) have jointly agreed to return to the NBTC a portion of 5 MHz of bandwidth from the unused 25 MHz on the 1800-MHz spectrum. DTAC's concession will end in 2018.
Mr Takorn said the return of 5 MHz from CAT and DTAC would benefit the telecommunications industry, as it would increase the bandwidth of each licence from 12.5 MHz to 15 MHz. This could eliminate an immense waste of spectrum from a block size of 2.5 MHz per licence.
However, the NBTC is determined to stick to the 4G auction's November schedule, so any possibility of an interruption will be rejected.
"The NBTC is set to auction 30 MHz of bandwidth by including the 5 MHz of CAT's proposal," Mr Takorn said. "If the labour union files a legal challenge with the administrative court asking for some compensation for the state enterprise, it could cause the auction to be suspended."
The secretary-general said the NBTC would keep to the original plan by auctioning only 25 MHz of bandwidth on the 1800-MHz spectrum if it looked like the auction could be suspended.
The heads of DTAC and CAT met last Friday with the NBTC secretary-general to discuss the issue.
DTAC insisted it supported CAT returning the unused 5MHz of bandwidth under its concession to the NBTC without any conditions attached.
Col Sanpachai Huvananda, CAT's president, said he would try to convince the labour union to support the proposal, which would benefit the overall industry and not just the company.
Mr Takorn said the NBTC was set to hold a public hearing on July 18 for the auction design for the 1800-MHz licence but wanted to clarify CAT's proposal beforehand.