All of the Tier 1 U.S. carriers have embraced Wi-Fi calling to varying degrees, with T-Mobile US (NYSE:TMUS) and Sprint (NYSE: S) more enthusiastic than AT&T Mobility (NYSE: T) and Verizon (NYSE: VZ) in deploying the technology. There are several ways operators have tried to launch Voice over Wi-Fi services in Europe. The first largely includes responses to Skype with peer-to-peer calling and messaging services, such as Orange's Libon service. The second includes downloadable applications such as Three's InTouch. Now, in the UK, the next generation of Wi-Fi calling -- where the service is embedded in the smartphone and accessed via the normal phone dialer -- is offering operators a way to take back control by enabling them to provide voice services in areas where they have little or no coverage due to poor signal strength. In this special report, FierceWireless:Europe takes a deep dive into the Wi-Fi calling landscape in the UK and how it is setting the stage for Voice over LTE. Special report