iPhone needs a data connection (via WiFi, GPRS or 3G) to connect to Internet. When you buy an iPhone from a telecom provider, usually it has been configured properly for GPRS/3G data connection. If your iPhone is not configured for GPRS/3G, you can contact your telecom provider for assistance or do the following steps:

Step 1: On your iPhone, select the Settings icon

Step 2: Select General > Network and enter the APN name, i.e. 

• If you are a Singtel user enter internet
• If you are a M1 user enter sunsurf
• If you are a Starhub user enter internet