Mobile network EE has launched live trials enabling customers to make voice calls over wi-fi and 4G connections, aiming to help connect people in part of rural Britain that have previously had poor service.

The move comes as part of the companys £275m investment in voice technology and capabilities, and will launch the wi-fi service in autumn 2014, with the VoLTE (Voice over Long Term Evolution) 4G calling service following in 2015. More than 6,000 2G sites are being upgraded as part of the launch, with capacity increased on a further 2.000 3G sites.

“Our wi-fi calling capability will let customers make calls where they have access to wi-fi but not to the mobile network,” said Fotis Karonis, chief technology officer at EE. “The customer experience is seamless because its the same as making a network call and uses the normal call interface of the handset.

“This is a major part of our strategy to invest in giving customers the ability to make a call wherever they are, and were confident that this service can make a big difference to people in homes and large offices across the country, especially in the most rural areas, that dont have mobile coverage.”

The shift towards 4G calling will also expand data and voice coverage, as the lower frequency spectrum has significantly greater reach than the higher band 3G signal. The later launch is so the technology has a chance to mature and gives EE time to reach 90 per cent population coverage with 4G, which is essential to a viable voice service.

EE has further initiatives in place to advance its voice technology and service, including using the MyEE app to identify white spots where service is unavailable, an ambition to halve its dropped call rate and its Platinum Project, which aims to create a zero defect experience for customers in the busiest areas of the UK.