GENEVA (Reuters) -- Smartphones are causing heavy congestion on the world's mobile networks and governments need to act quickly to support wireless broadband growth, the head of the International Telecommunications Union warned on Friday.
High-tech mobiles such as Apple's iPhone consume five times more data than traditional handsets, straining mobile broadband capacity in many areas, ITU Secretary-General Hamadoun Toure said.
While mobile operators have invested billions to upgrade and improve the capacity and performance of networks, there are bottlenecks in New York, London and San Francisco and elsewhere.
"We are still seeing users frustrated by chronic problems of network unavailability," Toure said in a statement calling for better national planning.
The number of smartphones in use worldwide is expected to swell to 2 billion by 2015 from 500 million today, according to the ITU, a Geneva-based United Nations agency.
"Robust national broadband plans that promote extra spectrum and the faster rollout of fibre networks are vital to support the number of data-intensive applications," Toure said.
U.S. President Barack Obama announced plans on Thursday to expand high-speed wireless Internet to 98 percent of Americans and to free up more wireless spectrum space over the next decade to cope with growing demand from users of smartphones and gadgets such as the iPad.
According to ITU figures, only 98 countries have specific broadband plans in place, though 90 percent of the world is now covered by a mobile signal.
Operators have been coping with capacity strains by penalising heavy data users among other measures, the ITU said.
It stressed proactive steps to support mobile broadband growth would help avoid "capacity crunch," especially in emerging markets.
"Mobile broadband is increasingly the technology of choice for hundreds of millions in the developing world, where fixed-line infrastructure is often sparse and expensive to deploy," the ITU said.
There will be 1 billion mobile broadband subscriptions worldwide in the first quarter of 2011, according to the U.N. agency's estimates. As of last year, 73 percent of the world's mobile cellular subscriptions were in developing countries.
Smartphones have revolutionised the mobile industry for network operators and handset makers.
Nokia, the world's largest cellphone maker, has teamed up Microsoft to compete against the iPhone and products based on Google's Android platform, used by rivals such as HTC Corp and Motorola.
Canadian telecoms firm Telus said on Friday its quarterly profit rose 46 percent, thanks largely to strong data and wireless revenue, and rival BCE Inc saw profit rise 25 percent due to growth in the number of high-end smartphone users.
Editing by Laura MacInnis and David Hulmes