How the GSMA is helping the VoLTE market to grow

david-o-crop By David O’Byrne, Project Director, GSMA


There have been 507 LTE network launches in 170 countries worldwide so far – a figure that continues to grow – and this exponential rise in deployments has laid the foundations for mobile operators to provide all-IP based services such as Voice over LTE (VoLTE), Video over LTE (ViLTE), Voice over Wi-Fi (VoWiFi) and the Universal Profile for Rich Communications Services (RCS). These technologies are helping operators to upgrade their traditional voice and messaging services and deliver ‘advanced communications’ to their customers such as pre-calling, instant messaging, live video and real-time photo or file sharing which work natively on any device and network without the need to download an app. Operators are in a unique position to offer secure, ubiquitous all-IP solutions that not only match those offered by Online Service Providers (OSPs) but are in many cases superior to them. This is particularly true when we consider the enhancements made through network interconnection as well as the quality and reliability customers are guaranteed from their network provider.

Voice remains a key and fundamental operator service and VoLTE is helping to enhance the customer experience with features including HD voice and fast call set-up times. To date there have been 82 commercial operator launches in 46 countries. However, the speed of these deployments has been hampered by fragmentation in implementation of the VoLTE specification. A lot of our work in VoLTE has been in encouraging everyone from operators to device manufacturers to follow a common approach that removes this fragmentation and makes it easier for new VoLTE launches to happen quickly and uniformly. Interoperability and interconnection are key to this. For example, the lack of interoperability between a device and a network has created problems for device OEMs who have struggled to adapt their products due to the varying technical demands of different networks in different markets. This lack of a one size fits all approach has meant that each device must be configured to each individual network which has been a needless and time consuming process.

To combat this we updated the VoLTE technical specification to give all users a minimum functionality set for all–IP based voice and SMS communications over LTE. It is designed to remove market fragmentation by removing complexity, ambiguity and options in the GSMA specifications which will simplify network deployment. This will optimise VoLTE and provide a high degree of commonality and interoperability, while retaining enough flexibility for MNOs to deal with unique and regional needs in a managed way. We also developed a common format for device configuration parameters, and are developing a solution to allow Operators to securely share these parameters with their OEMs. On first configuration upon SIM-insertion, the OEM can look up the specific MNO configuration settings in the GSMA database and configure the device appropriately. These developments will enable any participating OEM to build one standard device for multiple regions.

The new specification captures the lessons learned from over 70 VoLTE deployments as well as feedback from mobile operators, OEMs and other vendors. So far over 550 issues have been captured and organized into the GSMA N2020’s IP Communications Shared Solutions Registry (IPSSR), of which 95% have been solved, Indeed, the GSMA has a wide variety of resources available that can help organisations manage details such as cost, time to market and device availability, as well as gain access to the updated specifications. All of this will help with driving faster and more efficient VoLTE deployments and ensure that future deployments enjoy broad device availability. To find out more please go to

We are already starting to see real market impact as a result of our effort with seamless roll-outs by operators in China and commitments from other major markets including Germany and Russia. By working collaboratively and with common technologies, we can make positive changes in the market that will enhance the communications experiences of mobile subscribers from around the world.

To find out more about the GSMA’s Network 2020 programme, go to