“Network architecture” refers to how base stations and the core network are combined. Unlike 4G, 5G supports two network architectures: NSA (Non-Standalone) and SA (Standalone).
SA involves building an entirely new network, including new base stations, backhaul links, and a core network. It uses 5G base stations on the radio access side and a 5G core network. NSA, by contrast, uses existing 4G infrastructure to deploy 5G. In this architecture, 4G and 5G base stations coexist on the radio access side, with either a 4G or 5G core network. Compared with SA, NSA offers advantages in three main areas:
First, it can use mature 4G networks to extend 5G coverage, increasing the coverage area of individual 5G sites through joint deployment with 4G.
Second, NSA standards were developed earlier, and the corresponding product development and testing work is largely complete, resulting in more mature products.
Third, in an NSA deployment, 5G base stations can use the existing 4G core network, eliminating the need to build a 5G core network.
In the early stages of 5G deployment, NSA enables rapid, large-scale 5G coverage by upgrading existing 4G base station infrastructure. This saves time and money, giving NSA a significant advantage for rapid 5G rollout. However, SA is the ultimate architecture for 5G.
