5G NSA Vs. SA: How Does Each Deployment Mode Differ? - TechTarget

Non-standalone 5G

For NSA 5G, the clue is in the name: It's 5G that can't stand on its own in terms of infrastructure. NSA is a 5G RAN that operates on a legacy 4G LTE core, known as Evolved Packet Core(EPC), and manages control plane functions. NSA includes a 4G and 5G base station, but the 4G base station takes precedence. Because the NR control plane anchors to the EPC, radio frequency signals are forwarded to the primary 4G base station.

This article is part of

Enterprise 5G: Guide to planning, architecture and benefits

• Which also includes:
• What is 6G? Overview of 6G networks & technology
• Top 5 use cases for 5G augmented and virtual reality
• What 5G skills are most in demand?

NSA 5G, also known as Release 15 by 3GPP, is considered the first stage of 5G. Initial 5G deployments relied on NSA because MNOs with 4G LTE networks could implement a 5G RAN on their existing infrastructure to build a 5G network. NSA 5G can serve as a stepping stone for carriers unprepared to make a hefty investment when transitioning from legacy 4G LTE to 5G networks.

However, NSA 5G can't deliver the specific features and capabilities offered by a natively built SA 5G network. Ultra-low latency, a hallmark of 5G, isn't enabled by NSA networks. Another disadvantage of NSA is that it isn't as energy efficient as SA; 5G networks underpinned by 4G infrastructure require more power. Although 5G NR is more energy-efficient than LTE, using two different forms of cellular technology can massively increase power consumption.

NSA 5G shouldn't be confused with dynamic spectrum sharing (DSS), another method for deploying 5G using 4G technology. While NSA creates a 5G network using 4G infrastructure with dual connectivity, DSS permits 4G LTE and 5G NR to coexist in the same frequency band. 5G networks have a variety of spectrum bands available for use, and DSS distributes spectrum between bands based on user demand.