In 5G, SA (Standalone) and NSA (Non-Standalone) refer to two deployment modes of the 5G network architecture, each with distinct characteristics and implications for the evolution of mobile communication. These deployment modes represent different approaches to implementing 5G services and are significant in understanding the transition from previous generations of wireless technology to the full-fledged 5G ecosystem.
- NSA (Non-Standalone):
- Definition: NSA represents the initial phase of 5G deployment where the 5G radio access network (NR – New Radio) is supported by the existing 4G LTE core network (EPC – Evolved Packet Core). In this mode, the 5G network relies on the LTE infrastructure for certain core network functions.
- Deployment Steps: The NSA deployment allows for a quicker introduction of 5G services by leveraging the existing LTE infrastructure. It involves the deployment of 5G NR cells (gNBs) alongside LTE cells, and both radio access technologies work in conjunction. The 5G NR provides enhanced data rates and connectivity while utilizing the LTE core for control functions.
- Advantages: NSA enables a more rapid rollout of 5G services, leveraging the existing LTE network’s foundation. It allows for improved data rates and capacity, making 5G services available sooner to users.
- SA (Standalone):
- Definition: SA represents the full-fledged 5G network architecture, where both the radio access network (5G NR) and the core network (5GC – 5G Core) are entirely built on new 5G technologies. In this mode, the 5G network operates independently without relying on any 4G infrastructure.
- Deployment Steps: The transition to SA involves deploying a standalone 5G core network, which includes new elements and functionalities. SA enables the full realization of 5G capabilities, including advanced features like network slicing, low-latency communication, and enhanced support for massive IoT (Internet of Things) deployments.
- Advantages: SA provides the complete set of 5G features and benefits, unlocking the full potential of the technology. It allows for more advanced use cases and services that leverage the unique capabilities of the 5G network.
- Coexistence and Transition:
- During the transition from NSA to SA, operators may initially deploy NSA to offer early 5G services while building the infrastructure for a standalone 5G core network. This phased approach allows for a smoother evolution toward a fully independent 5G network.
- Evolutionary Path:
- The progression from NSA to SA reflects the evolutionary nature of 5G deployment. As the ecosystem matures, operators move towards the standalone architecture to fully exploit the transformative potential of 5G technologies.
In summary, NSA and SA in 5G represent two deployment modes that highlight the evolutionary path of 5G networks. NSA allows for a quicker rollout by integrating with existing LTE infrastructure, while SA represents the complete, standalone 5G architecture with advanced features and capabilities. The coexistence and transition between these modes enable a phased approach towards realizing the full potential of 5G.