The pace of voice over LTE (VoLTE) service launches is picking up worldwide. Currently, around 200 operators have launched VoLTE services in around 100 countries, and more than 250 operators are investing in VoLTE in more than 120 countries.
Nevertheless few operators have implemented VoLTE roaming that would provide a seamless service for their customers when out of range of their home networks. When VoLTE subscribers roam internationally or even within their own countries, their voice calls will most likely use a local 3G network – also known as, circuit switched fallback (CSFB) – rather than a local 4G LTE network.
This is not ideal for operators or their customers. While roaming on 3G networks, subscribers don’t have access to the rich VoLTE features they enjoy on their home networks. And until VoLTE roaming becomes pervasive, operators can’t shut down legacy 3G networks and re-use that spectrum for advanced 4G or 5G services, which is one of the main benefits of VoLTE.
