Third operator to introduce the service will use other technologies as back-up Mobile operator CSL is taking a cautious approach in its 3G roll-out, deciding to charge a premium for video calls and using wi-fi and 2.75G technologies to back up its service. The mobile arm of Australia's Telstra Corp yesterday became the third operator to launch a 3G service in Hong Kong, after Hutchison Telecom and SmarTone Telecommunications Holdings. Chief executive Hubert Ng Ching-wah said the company would sell dual-mode handsets capable of both 3G and wi-fi, a fixed wireless technology that is said to have the potential to steal mobile operators' voice revenue. At present wi-fi is mostly used for transmitting data. Initially the company would introduce the Nokia 9500, an Edge (or 2.75G)/wi-fi dual-mode phone, Mr Ng said. 'The long term is for 2G, 3G, wi-fi or wimax [to be used] as an integrated network ... we are looking at 3G handsets that are also wi-fi capable,' he added. CSL's wi-fi service allows users to access the internet at fixed locations, referred to as 'hotspots', wirelessly with their own handheld devices. The firm has 90 hotspots in Hong Kong. Japan's mobile giant NTT DoCoMo launched a dual-mode wi-fi-capable phone last month, enabling customers to use mobile voice-over internet protocol (VoIP) and 3G on the same handset. In Hong Kong, PCCW is also testing a phone that can perform VoIP over wi-fi and BT will launch a similar mobile wi-fi phone by the end of next year. Analysts say that in the future operators will look to a fixed mobile convergence model, which combines wi-fi or wimax with 3G mobile services to offer a users seamless mobile connection. 'It is possible that mobile VoIP will kill mobile operators' revenue but we don't expect this to happen until 2015 at the earliest,' an investment bank analyst said. Thus, mobile operators offering VoIP service over wi-fi are equipping themselves for the challenge from fixed-line operators. Meanwhile, Mr Ng said CSL would have at least 10 different 3G handsets by the third quarter of next year. CSL would soon launch Motorola E1000, also sold by SmarTone and Hutchison. CSL is targeting an average revenue per user of between $300 and $500 for 3G over the longer term. However, unlike SmarTone and Hutchison, CSL did not bundle free video call minutes into its service plans and would instead charge an extra $1.50 per minute for the service. 'The demand for video call service is not there yet,' Mr Ng said. His company still considers it a premium service. For now, data coverage in all the MTR tunnels was provided by Edge. Mr Ng said whether this would be upgraded to 3G would depend on market demand. CSL's 3G tariff plans are set at $188 to $338. Sunday Communications is the only one of Hong Kong's four 3G licensees that has yet to launch its service.