Introduction
In this evolving world of telecoms, the advent of 5G technology has brought forth a myriad of deployment strategies, each with its unique implications and advantages. As industries race to embrace the potential of 5G networks, understanding the nuances between standalone (SA) and non-standalone (NSA) architectures becomes paramount. Let's delve into the intricacies of these deployment methods and explore their significance in the realm of network transition and advancement.
Understanding 5G network deployment strategies
5G network deployment involves various strategies, including the deployment of both standalone (SA) and non-standalone (NSA) architectures. Let's break down what these terms mean and how they relate to a network swap scenario:
- Non-Standalone (NSA) 5G: NSA refers to the deployment of 5G networks that are built upon existing 4G LTE infrastructure. In this scenario, both 5G radio and 4G radio access networks are present. Two access networks inter work using dual connectivity to provide a combined radio access to UEs. Core Network can either belong to 4G (EPC) or 5G (5GC). Initially in NSA, option 3 is widely used (EPC present), then in later stages option 7 & option 4 (5GC present) can be used by telcos before shifting to 5G SA. NSA deployment is used by most of the network operators with existing 4G infrastructure today.
This allows for faster deployment of 5G services since it piggybacks on the existing 4G infrastructure. However, it doesn't fully leverage the capabilities of the 5G network.
- Standalone (SA) 5G: Only one radio access technology is used. For 5G SA deployment, Independent 5G network (Radio & Core) is used and it is known as Option 2. This option is widely used by Greenfield 5G Networks. Similarly, 4G SA is known as Option 1.
In SA mode, with just 5G radio access presence, both control and user planes are handled by the 5G core network, allowing for more advanced features and capabilities, such as network slicing and ultra-low latency. However, deploying SA networks typically requires more time and investment as it involves building the core network from scratch and a large number of 5G base stations provide ubiquitous coverage.
Note: In NSA, two access nodes are known as master and secondary node. In the case of option 3, both control and user plane will route through 4G access network only. Option 3a and 3x are the evolved version of option 3 basis flexibility of routing of user plane. Control Plane must route through Master node whereas User Plane can route directly from 5G access network to 4G core network in Option 3a and through either master access node or secondary access node in Option 3x. There are two more SA options - 5 & 6. These options are not used for deployment. Migration to 5G needs to be carefully planned and evaluated by telcos from business as well as from current network architecture prospective.
Transitioning from NSA to SA
In a network swap scenario, a transition from NSA to SA may occur. Here's how it might happen:
- Assessment and Planning: The first step involves assessing the existing network infrastructure and determining the requirements for transitioning to SA 5G. This includes evaluating the presence of number of 5G base stations to provide ubiquitous coverage and evaluating the presence of modular core node functions required to support SA 5G with the relevant SW to support it. Also, need to ensure that the major proportion of existing user devices support SA 5G.
- Deployment of SA Network: The evolved SA core and radio network infrastructure needs to be deployed. This includes installing new nodes, such as base stations (including disaggregated virtualized/cloud nodes), servers, scalable modular cloud native core node functions with CUPS architecture with right updated SW based on recent 3GPP release.
- Integration with Radio Access Network (RAN): The SA core network needs to be integrated with the 5G disaggregated RAN, which includes distributed and central units with efficient interfaces on front haul. Also, it involves configuring the RAN to communicate with the new core network and ensuring compatibility and interoperability between the two.
- Testing and Optimization: Once the SA network is deployed and integrated, extensive testing is conducted to ensure that it meets key performance indicators. This includes testing for interoperability, coverage, throughput, and latency etc.
- Optimization and Fine-tuning: After migration, the network undergoes further optimization and fine-tuning to address any performance issues and ensure optimal resource utilization.
Transitioning from NSA to SA involves a comprehensive process of deploying new infrastructure, integrating existing components, and ensuring a smooth migration of subscribers. It requires careful planning, coordination, and testing to minimize disruptions and deliver a seamless 5G experience.
Enabling Standalone 5G: Infrastructure Upgrades and Innovations
There are few examples of Standalone deployments in 5G where 5G Standalone Core are deployed either on hybrid or public cloud and leveraging hyperscaler’s infrastructure and innovation. On Radio Access Network also, we have observed a mix of deployment from proprietary hardware to COTS hardware with disaggregation of baseband units into distributed and central units. Connectivity among these nodes especially in disaggregated RAN with fronthaul have stringent requirements. Mix of fiber and E-band microwave (for backhaul) deployments are observed in the transport network.
In nutshell, enabling SA 5G means a complete upgrade of infrastructure right from access to transport to core network and focused on software-based cloud infrastructure that enables a flexibility to place the 5G network functions/applications and divide the single infrastructure into multiple network slices for delivering wide range of services from eMBB to URLLC. Such infrastructure helps to add services faster, respond quickly to changing demands, and manage resources efficiently and automatically. Some of the key building blocks could be network function virtualization (NFV), software defined network (SDN), edge computing, and microservices. NFV allows to abstract functions away from hardware, allowing standard servers to be used for functions that otherwise require proprietary hardware. SDN is an emerging architecture for midhaul/backhaul that is dynamic, manageable, and adaptable, making it ideal for dynamic nature of 5G applications. This architecture decouples the network control and forwarding functions enabling the network control to become directly programmable. Microservices break down network functions and applications into loosely coupled systems that are resilient, observable, and simple to manage using DevOps cycles and CI/CD approach.
In our next article, we will delve deeper into the 5G market and the opportunities it presents to telecom professionals. Stay tuned by following LabLabee page and expert Mr Rahul Kaundal on LinkedIn.
About Rahul Kaundal:
Rahul Kaundal is a seasoned telecom professional, working in the technology sector and in his career, he has led different Telco Network Projects including their Design, Operations, Excellence & Evolution right from 2nd Generation Technology to 5th Generation. His core focus areas are Radio access Network, Transport Network, AI/ML, Automation & Cloud systems. He believes in sharing knowledge, and he has built an e-learning platform exclusively for telecom industry– itelcotech.
