Despite the rise in usage of WiFi Calling, and of over-the-top services from WiFi handsets, concerns remain about quality of service in unlicensed spectrum, especially when users are outside the well-controlled environment of a home or enterprise WLAN. Republic Wireless, one of the US’s clutch of WiFi-first MVNOs, claims to be addressing that issue with a technique called Bonded Calling. Its engineers have developed technology which senses WiFi network conditions and responds to issues by patching the gaps in a WiFi call using cellular back-up. This fits well with the WiFi-first ethos – in which users default to WiFi but are transferred seamlessly to cellular connections when the WiFi signal is poor (they only pay fees when they are moved…