Carriers expected to go into 4G overdrive between 2012 and 2014

Service providers believe 4G download speeds will be 25Mbit/s to 50Mbit/s at launch

Majority of 4G rollouts expected after 2012

The majority of operator rollouts of fourth generation (4G) networks will take place between 2012 and 2014, according to the 4G Strategies:Global Service Provider Survey by Infonetics Research.

The top two challenges for 4G operators are the capabilities and availability of 4G devices, and the architecture used to deliver voice services.

The biggest technical driver for upgrading to 4G for operators is "it's better spectral efficiency", said Infonetics microwave and mobile device analyst Richard Webb.

Better spectral efficiency, or radio spectrum use, means more users and services can be supported simultaneously.

Infonetics said that half of the service providers it surveyed believe that 4G download speeds would be between 25Mbit/s and 50Mbit/s at launch, while 42 per cent "believe downlink speeds will be in excess of 50Mbit/s, suggesting that operators are getting more ambitious."

The mobile enterprise business is of growing importance, with 82 per cent of service providers saying they plan to launch mobile VPN services.

Currently UK mobile operator deployments of 4G technologies are being held back by negotiations in the comms industry about the distribution of radio spectrum required for 4G operation.

Key 4G wireless technologies include Long-term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMax).