With more than four million users - half of all mobile subscribers - on 4G services, the Government is finally requiring telcos to meet service standards currently imposed only on 3G services.

With this, Singapore has joined Baltic nation Latvia to be among the first in the world to implement such requirements.

The new rules would require telcos' 4G networks to cover at least 95 per cent of all outdoor areas from next month. The requirement will be expanded to 99 per cent from July next year. Networks are considered to have "covered" an area if a phone shows at least one bar of signal strength - enough to make phone calls and send text messages.

Telcos' 4G networks must also cover 85 per cent of all floors including basement one from January 2019. Tunnel coverage must be at least 99 per cent from July 2018.

"In this world, connectivity is almost a basic right," said Mr Gabriel Lim, chief executive-designate at the newly formed Infocomm Media Development Authority (IMDA).

IMDA is the result of a merger between the Infocomm Development Authority and the Media Development Authority.

"Based on preliminary sensing, our telcos have already achieved this standard... They also have a one-year timeline to achieve the stretched target of 99 per cent outdoor coverage," he said.

Mr Lim was delivering the opening address at the region's largest communications trade event CommunicAsia at Marina Bay Sands yesterday. The show ends tomorrow.

Singapore's potential fourth telco must also start meeting 4G service standards from October 2018.

The 4G service standards have taken reference from 3G ones, which were progressively tightened from 2012 to 2013. For instance, telco 3G networks must cover at least 99 per cent of outdoor areas, and 85 per cent of all floors including basement one in buildings.

An operator which fails to meet the various 3G and 4G standards may be fined up to $50,000 every month for each breach.

Consumers cheered the move.

Businessman Harry Chew, 46, said that his 4G connection falls back to 3G every now and then, especially in buildings and tunnels. "It doesn't make sense that I'm paying for 4G connection but I get 3G instead," he said.

Ms Christine Lai, 56, a sales and marketing executive, said she even gets the older General Packet Radio Service - 2.5G - signal on her phone instead of 4G when she goes to some parts of Sengkang and Woodlands.

"I hope the minimum services standards will compel the telcos to improve 4G coverage," she said.