PARTNER FEATURE: The sun is setting on legacy 2G & 3G networks and the momentum is building globally. A GSA report from October 2022 noted that 142 operators were actively planning or progressing sunsets. Of these, 51 had already completed the decommissioning of a 2G or 3G network as they consolidated on 4G and/or 5G. GSA forecasts that sunsetting will reach a peak in 2025.

The greater spectral efficiency of newer technologies, and the ability to re-farm 900 MHz and 1800 MHz 2G spectrum or 2100 MHz 3G spectrum to extend the coverage of 4G or 5G are just two motivations. Eliminating legacy technologies will reduce network complexity and deliver operational efficiencies as well as helping to meet sustainability targets by reducing power consumption at a time of soaring energy costs.

At the same time that operators are considering the future of legacy network technologies, they are also keen to take advantage of the flexibility, agility and improved time-to-market offered by the cloud.

However, 4G and 5G were primarily developed to meet burgeoning demand for mobile broadband in the internet age. Yet voice remains important: it’s the foundational and most intuitive of telecom services. Roaming remains a highly valued, and valuable, service for users and operators alike. Most operators are still obliged to carry calls to the emergency services.

2G remained the primary bearer for voice traffic throughout the 3G and the early years of the 4G eras. Voice over LTE (VoLTE) based on the IP Multimedia Subsystem (IMS) architecture was eventually introduced to carry voice calls across 4G networks. It also became the fall-back voice solution for initial 5G Non-StandAlone deployments. VoLTE is being adapted to create Voice over New Radio (VoNR), a new IMS network function, for 5G StandAlone.

IMS & the cloud

IMS has become the go-to architecture for delivering high-quality digital services. With VoLTE, VoNR, and HD Voice capabilities, IMS makes it easier for operators to continuously update and enhance their offerings with new, innovative experiences for their customers.

As the deployment of 5G and FTTX accelerate across the wider telecoms sector, IMS can support converged and unified networks that provide centralized session control and multimedia service offerings with uniform user experiences across the different access methods.

While IMS is well suited to cloud deployments, making IMS services truly “cloud-native” is key to maximising the benefits. A cloud-native approach delivers and enhances flexibility, agility and scalability and improves product velocity. Additionally, a cloud-native infrastructure can enhance service orchestration, partner ecosystems and product innovation.  Cloud-native solutions can replace manual with automated procedures to enable automated zero-touch deployment.

Use of cloud computing design and architectural concepts is required to fully leverage cloud capabilities, whether on public, private, or hybrid clouds. The use of microservices in software development enables the adoption of a continuous integration, continuous testing, and continuous delivery (CI/CT/CD) approach which can shorten development cycles and lower the risk of human error. Applications that can be made stateless can become almost infinitely scalable.

Wholesale VoLTE in Mexico

Mexican operator Altán Redes has adopted the cloud native approach for what is arguably one of the most ambitious VoLTE use cases in world. Since winning a government tender to improve mobile phone penetration and network coverage across Mexico’s vast territory Altán Redes has been building an open-access wholesale 700 MHz 4G network known as Red Compartida. The network combines new 4G infrastructure with resources shared by incumbent operators. Services are marketed to consumers by the partner MNOs and other MVNOs that offer domestic mobile phone and fixed internet services.

VoLTE is the only way to carry and guarantee calls across the new agnostic 4G network. The IMS solution also offers subscribers improved call quality, the ability to browse while calling and enables interconnection with the 3G networks of other operators. In the future, it will also allow for easy migration to 5G.  The cloud-native IMS VoLTE solution, which supports LTE voice and SMS services, has been provided to Altán Redes by JSC Ingenium.

Cloud agnostic

By adopting the open-source Cloud Native Computing Foundation (CNCF) software foundation, dependency between the application and the underlying platform has been eliminated: JSC Ingenium’s VoLTE IMS is designed to be cloud agnostic and allows operators to work with their own preferred operational environment.

Through the use of Kubernetes, the VoLTE IMS solution can scale from a system capable of supporting as few as 30 calls a second up to millions of busy-hour calls. Smaller start-up operators can run a smaller system off a single PC while the solution has also been deployed on the public clouds of the hyper-scalers. One tier one operator is running the solution on its own private telco cloud running in its own container-as-a-service. Outside busy hours, resources can be off-loaded to minimise operational costs. This flexibility means the operator cannot be locked-in to any one cloud environment. A fully cloud native VoNR solution has now been released to complement VoLTE.

For any operator needing to sunset 2G or 3G, cloud-native IMS VoLTE and VoNR network functions provide the means to start the transition to a more agile cloud-based business while ensuring they can continue to offer the foundational voice and messaging telecommunications services.