The National Broadcasting and Telecommunications Commission (NBTC) will impose strict measures governing the quality of mobile phone signals.
The move aims to address the large number of complaints concerning dropped calls, the main complaint from mobile phone users.
NBTC secretary-general Takorn Tantasith said the measures are also aimed at ensuring mobile networks maintain a high quality.
Dropped calls are telephone calls which, due to technical reasons, are cut off before customers hang up.
The NBTC's board last week discussed the issue with major mobile operators.
Mr Takorn said the regulator plans to amend certain conditions defined in the existing regulations governing the quality of mobile services to ensure mobile signals meet a certain standard.
Under the current regulations, the dropped-call rate (DCR) of a mobile company must not exceed 15% of all calls in a network.
Mr Takorn said the existing rule is impractical because the DCR in some congested traffic areas was much higher than average.
"We are prepared to force mobile operators to maintain their DCR for calls at 15% or below in each service area," he said.
The new regulation is expected to take effect by September, he said.
Mr Takorn acknowledged that operators needed to boost their subscriber base in order to optimise their investment in networks, resulting in network traffic congestion in some areas.
The NBTC has given five mobile operators 15 days to resolve their dropped-call problem. The five are Advanced Info Service (AIS), Total Access Communication (DTAC), True Move, CAT Telecom and TOT Plc.
As of May, he said there were 994 complaints involving dropped calls for AIS, followed by DTAC (497), True Move (386), CAT Telecom (32) and TOT (seven).
The highest DCR happened in Bangkok, mostly in Klong Toey, Chatuchak, Bang Khen, Bung Kum, Bang Na and Wattana districts.
Over 30 provinces accounted for most of the complaints.
Mr Takorn said the number of complaints is soaring again now that operators are gearing up their customer acquisition strategies to optimise their investment in the 4G network.