Breaking Barriers: The Future of Sponsored Roaming with VoLTE

In the ever-evolving landscape of telecommunications, roaming has long been a critical aspect of connecting people across borders. With the advent of Voice over LTE (VoLTE), the potential for seamless, high-quality voice calls while roaming has become a reality. However, the journey towards VoLTE roaming, particularly in the realm of sponsored roaming, has been fraught with challenges.  

VoLTE, the technology that enables voice calls over 4G LTE networks, represents a significant advancement in voice communication. Its benefits include faster call setup, clearer audio quality, and the ability to use data services during a voice call. Yet, the implementation of VoLTE roaming has been hindered by various technical and logistical obstacles. 

Sponsored roaming allows new MNOs and MVNOs to get instant worldwide roaming coverage through an IMSI range provided by Vodafone, gaining access to an extensive reach via our roaming agreements with 700+ operators worldwide. However, integrating VoLTE capabilities into sponsored roaming arrangements has presented unique challenges. One major hurdle is accommodating the customer's own Original Equipment Manufacturer (OEM) customization package for VoLTE roaming and matching it with the sponsor IMSI.  

Unlike other technologies, VoLTE requires handset customization specific to each MNO. This means that every MNO must collaborate with device manufacturers to incorporate their unique VoLTE parameters into the handset's VoLTE stack, which is referred to as the customization package. When it comes to sponsored roaming, the situation becomes even more complex. There are multiple methods recommended by GSMA however some sponsored roaming customers, such as smaller MNOs and Mobile Virtual Network Operators (MVNOs), often lack the bargaining power to negotiate with device manufacturers to overcome these barriers.  

Despite these challenges, the teams at Vodafone Voice and Roaming Services (VRS) identified a solution to overcome this obstacle, facilitating the successful activation of VoLTE roaming for sponsored customers without any hindrance. Thanks to their efforts, we were successful to enable VoLTE calls while utilizing the sponsor IMSI and our customer’s own VoLTE customization package.  

With this advancement, VRS now offers VoLTE for sponsored roaming catering to any customer’s requirements and specific network setup.  

I’m really proud of the team, who worked collectively to find smart solutions to these unique challenges. In particular, I’d like to thank Andrew Chalmers and George Coslet for their innovation, hard work and diligence on this project. Together, no challenge is too big - on to the next!