SINGAPORE - Singtel will roll out Singapore's first commercial Voice over Wi-Fi (VoWiFi) service in August following trials at the Jurong Lake District.

Along with other service providers, Singtel was conducting trials of its Heterogeneous Network (HetNet) at the District.

HetNet is a new wireless system that allows users to automatically switch between Wi-Fi and cellular networks, like 4G, in order to minimise surfing delays and disruptions.

"The trial found that Singtel mobile users could make voice calls and text over Wi-Fi in areas that are technically challenging for mobile signals, as their smartphones switched seamlessly between mobile and Wi-Fi networks," Singtel said in a statement on Tuesday (June 21).

This will allow Singtel mobile users to make uninterrupted calls and send messages over Wi-Fi in locations such as basements and buildings above 20 storeys high, Singtel said.

The VoWiFi service will be available at any accessible Wi-Fi hotspot including homes, Singtel premium Wi-Fi and Wireless@SG locations, said Singtel.

The trial also demonstrated the readiness of Singtel's HetNet to support the Internet of Things, it said.

For example, it could provide a reliable, 24-hour connection to a real-time air quality sensing device tracking the Pollution Standards Index and carbon dioxide levels.

"Given our positive trial results, we are ready to support the Internet of Things with our networks and provide Singtel mobile users with high quality voice calls and SMS island-wide," said Mr Yuen Kuan Moon, CEO of consumer Singapore at Singtel.

Ninety per cent of trial users had a better user experience with faster speeds and smooth transitions between wireless and cellular networks, said Mr Gabriel Lim, co-managing director of the Infocomm Development Authority (IDA).

The Jurong Lake District trial was conducted at crowded spaces such as malls, MRT stations, HDB neighbourhoods and on board a bus.

Telcos M1 and Starhub, and Internet service provider MyRepublic were also involved in the trials.