Wi-Fi access can be used for telephony services for several subscriber and enterprise scenarios. However, the primary use case for Wi-Fi calling is to complement indoor environments where cellular network coverage is limited.
That said, there are other scenarios, where Wi-Fi calling can complement VoLTE. In some conditions, video calls may only be possible over Wi-Fi, even if the cellular network can carry voice. Subscribers may want to force a video call over the Wi-Fi network if the traffic generated is counted as part of their data bucket.
Holes can occur in suburban homes, but they also arise in densely populated areas where, for example, the use of energy-efficient building materials makes indoor coverage difficult. Devices are evolving, so that native support for the use of unmanaged Wi-Fi is now being included. And Wi-Fi calling supports advanced enterprise features, like short numbers, possible through IMS, enabling users to enjoy the experience of a modern smartphone within the context of enterprise telephony.
Wi-Fi calling connections are routed over the open internet, which enables operators to provide subscribers with voice services free of roaming charges as they travel outside of the home network. This capability uses a device’s native telephony client, and so improves the seamless experience.