The City of London WiFi network has only registered 6,000 users in its first month out of a possible 350,000, despite offering the service for free.

Such disappointing take-up in the Square Mile raises fears that on-street wireless access will not be commercially viable.

The Cloud, the firm that runs the London network, is bolstering its income with services for the local council, such as linking video surveillance cameras.

The firm also wants to team up with mobile operators to increase take-up of WiFi by bundling it into phone handsets, says co-founder Niall Murphy.

‘We are trying to deliver a mobile web experience,’ he said.

But the business model for outdoor web access is unclear.

Elliott Mueller, chief executive of Manchester’s Metronet WiFi network, says the concept of wireless cities is flawed.

‘I am not convinced that a sufficient market exists,’ said Mueller.

‘It is difficult to get people to pay for WiFi because they have internet access at home and outdoor coverage is patchy,’ he said.

Convergence of mobile internet and telephony is a growing trend. Research in Motion expects to sell a BlackBerry device this year with mobile voice and WiFi. And Nokia and Motorola have developed dual capability handsets.

But progress has been slow because mobile operators want to protect call revenues, says Forrester Research analyst Phil Sayer.

‘Mobile networks are wary of letting WiFi operators move into their space.’