EE has announced live trials of phone calls over Wi-Fi and 4G which could lead to improved audio quality and eliminate dropped signals. The network is investing £275 million in voice calling technology, which could eventually lead to calls being made over data bandwidth rather than the existing voice infrastructure.

We already have many VoIP services, such as Skype and Viber, but EE doesn't plan to take those head on. Instead, if the trials are successful and the technology is pushed out, phones will automatically sense a Wi-Fi connection - either public, in an office or at home - and connect the call through that method rather than general voice. It will use the normal call interface of the handset with the user needing to do anything out of the ordinary.

This would mean that you could make calls when in a London Underground station, for example, using Virgin Media's Wi-Fi network. You can with Skype currently, but that requires a Skype subscription or, for a free call, the person at the other end of the line also logging into the service.

READ: What is 5G, when is it coming and why do we need it?

The EE Test Lab will also start a trial of its live 4G call services using the 800MHz spectrum it acquired in the bandwidth auction last year. The 800MHz spectrum has a "significantly greater reach" than the 1800MHz spectrum used for 4G services, so can be used by the network to increase its geographical coverage of its data and voice network.

It will launch the capability in 2015. This will ensure that EE's 4G network will exceed the original target of 90 per cent UK coverage.

"4G calling, or VoLTE, is an exciting technology that we’re going to be trialling in the coming months using our low frequency spectrum, bringing voice and data services to a part of rural Britain that has previously been unconnected," said Fotis Karonis, chief technical officer of EE.

"When we have rigorously tested the performance of 4G calling and made sure that it matches our 2G and 3G quality, we’ll launch it nationwide on our 4G network."

Previously, EE explained to Pocket-lint that introducing integrated voice calling over the data network could even reduce bills in the future, although that isn't the immediate goal for these trials.