Thai regulator NBTC has approved plans to impose a 60MHz spectrum cap on the nation's mobile operators.
The regulator's telecom committee will impose the cap as a condition of participating in the 4G auctions at the end of the year, the Bangkok Post reported.
Mobile operators acquiring spectrum in the upcoming auctions of 1800-MHz and 900-MHz frequencies will need to return some of their existing holdings if the acquisition puts them above the 60MHz limit.
Dtac is expected to be hardest hit by the decision as it currently holds 75MHz of spectrum spread out across various frequencies.
The operator had argued that 60MHz of its holdings don't count as they were allocated under the old build-operate-transfer concession model, but the regulator has clarified that the cap will apply to spectrum held under concession as well as spectrum allocated under the licensing model.
This means if Dtac were to win 12.5MHz of spectrum in the upcoming auctions it would need to return 27.5MHz of spectrum – 12.5MHz to balance out the new spectrum secured, and an additional 15MHz to bring it under the 60MHz cap.
The NBTC tentatively plans to allocate four LTE licenses, two comprising of 12.5MHz of 1800-MHz spectrum apiece, as well as two 10MHz licenses for 900-MHz spectrum. The 1800-MHz spectrum is due to be auctioned in November, while a 900-MHz auction is expected to follow in December.