(Telecompaper) EE has announced live trials of phone calls over Wi-Fi and 4G as part of a GBP 275 million investment in voice to remove 'whitespots', and create 'zero defect' experience in UK's busiest areas. The Wi-Fi carrier grade service will allow people to make calls from their home, office, corporate or public Wi-Fi connection, and is scheduled to launch in autumn 2014. EE will also launch a trial of voice over LTE (VoLTE) 4G technology later in 2014 using 800 MHz spectrum. The trial will expand data and voice coverage, bringing service to a previously unconnected part of rural Oxfordshire. A full commercial launch of the capability will follow in 2015.