Total number of mobile VoIP users are expected to reach 288 million by the end of 2013, according to market research firm In-Stat.

According to In-Stat, over half will be associated with online mobile VoIP providers, under one-third will utilise mobile VoIP with 3G MVNOs or mobile operators and 11% with WiMAX/LTE operators.

On a geographic basis, mobile VoIP will be heavily biased towards the Asia Pacific region, particularly among the online mobile VoIP services.

The firm expects that the mobile VoIP applications will generate annual revenues of $35.2bn by 2013 and dual-mode handsets (Wi-Fi + cellular) will be well over 400 million units shipped in 2013.

While the EMEA region has more mobile VoIP related revenue currently, Asia Pacific will be the largest regional market in revenue terms by 2013, In-Stat said.

Frank Dickson, In-Stat analyst, said : “The near-term opportunity for mobile VoIP is closely linked with the growing success of dual-mode phones and other Wi-Fi connected devices.“However, mobile VoIP still poses a direct threat to operator voice revenue and operators are navigating how to balance new opportunity with the threat.”