Unused capacity in existing HSPA networks will satisfy UK demand for mobile broadband for the next four years, according to research from Informa Telecoms & Media. While there may be a perceived benefit in being first to market with next generation technologies, Informa said that it didn’t believe LTE deployments would make economic sense for UK carriers before 2015.

Due to the density of current HSPA networks, Informa said that it didn’t expect serious mobile traffic congestion to appear until 2013, and even then only in certain hotspots.

“Informa estimates that a new LTE deployment will cost an additional US$58m compared with upgrades to existing networks, assuming that the LTE deployment begins during 2013,” wrote senior analyst Dimitris Mavrakis. “Cost per gigabyte in the UK is forecast to be US$6.79 during 2011, gradually declining to US$2.74 during 2015. There is significant unused capacity in the network throughout the forecast period increasing the cost/GB above average values.”

Informa’s assessment of demand for LTE in the UK comes as other markets are pushing ahead with deployments. Earlier this week TeliaSonera announced that it had launched the first commercial LTE service in Finland, while US carrier Verizon wireless has said that it will switch on the 4G technology over the forthcoming weekend.