I complained last month that Hong Kong's mobile phone firms were gouging their subscribers over data services. My feeling was, and still is, that charging HK$16 to HK$300 per megabyte will only drive away the valuable early adopters the carriers are trying to attract. Those disenchanted customers are helping to build a new market that directly threatens the future of today's mobile carriers. Not surprisingly, several carriers protested that I had been a little harsh. They maintained that their charges for data services were reasonable, and that they had customers' interests at heart. To be fair, the carriers are gradually reducing their GPRS data charges. 'We don't want to kill the early adopters. We want them to stay with us,' says Stephen Chau, chief technology officer at Smartone. 'We want to gradually build the community and not threaten them.' Phone companies have always been reluctant to listen to their customers. In the past, this was because they could afford to - customers had little choice. Even today, there is little to differentiate most mobile contracts. But Wi-Fi could change everything. Far from being a laptop luxury, it is likely to become an indispensable part of any mobile-phone carrier's armoury. Some carriers even admit PCCW may not have been so dumb when it flogged its mobile networks to Telstra. As Peoples Telephone head Charles Henshaw points out on the opposite page, PCCW's muscle could be a potential defence rather than an old-world threat. Nokia has said there will be 100,000 hot spots globally by 2007, though that figure sounds desperately pessimistic. The recently formed Wireless Broadband Alliance, a pan-Asian group of mobile carriers, aims to have 20,000 hot spots ready for roaming by the end of the year - and that's just in Asia. The five founding members, China Netcom, Malaysia's Maxis, Singapore's StarHub, Korea Telecom and Telstra, Australia's top operator, plan to launch inter-operator Wi-Fi roaming by July. Last month, Hong Kong 3G licence holder CSL stepped out with several Asian carriers to announce the Asia Mobility Initiative, a regional mobile data deal that could be seen as a Wi-Fi competitor. In New York and London, local governments are pioneering citywide Wi-Fi networks, while idealistic geeks in cities from San Francisco to Paris have built community networks that anyone can access for free. Of course, in Hong Kong, the Office of the Telecommunications Authority had to step in and ban community networks. The move might protect certain wireless Internet service providers, but it should give little reassurance to those mobile operators who remain reluctant to change. There is also the significant hurdle of setting up a workable billing system. With users switching from free network to ISP to GPRS as they walk, sorting out how much everyone is due will be a huge challenge, even more so when some companies charge per byte, others charge per minute and some just give it away. But much of the equipment is already reaching the market. Cisco, IBM, Nokia and Ericsson all have gear that lets users automatically switch between cellular and Wi-Fi networks. This alone is remarkable when you consider that early GPRS phones forced users to choose whether to use their phones for voice or data. Networking firms like Nortel who have not yet begun production are looking like laggards. But even they should have products on the market within the next 18 months. It is the same story at the user-end. Nokia and Sony-Ericsson both have PC cards that can switch seamlessly between GPRS and Wi-Fi networks, while Motorola and Nokia are developing phones that integrate Wi-Fi. Texas Instruments has a prototype smart phone that combines tri-band GSM/GPRS, Wi-Fi and Bluetooth in a single device. Codenamed Wanda (for wireless any-network digital assistant), the device is a proof-of-concept to sell Texas chips to makers of personal digital assistants. But with Texas Instruments behind the design, it cannot be long before the firm releases communications chips or even microprocessors containing all four standards. Texas Instruments claims that manufacturers using the Wanda blueprint can have finished products within 100 days. With that kind of timescale, we could see Wandas on the streets by Christmas, though so perhaps Christmas 2004 would be more likely. Mr Chau admits Smartone is likely to roll out Wi-Fi services, though he says we are unlikely to see anything for at least two years. Wi-Fi, he says, still has its weaknesses, principal among these being patchy coverage and inability to maintain a connection while in a car or train. 'I am not discounting Wi-Fi. We are exploring how Wi-Fi and GPRS can complement each other when the price [and the technology] is right,' Mr Chau said last week. 'Wi-Fi or Edge, it is all the same to me. I never consider technologies one by one. Our job is to take away the barrier of technology.' That is exactly what every carrier should be saying.