5G SA and 5G NSA: Standalone vs Non-Standalone 5G NR

5G mobile networks have already been launched in many countries, but did you know that two types of 5G networks exist today? Standalone 5G (5G SA) and non-standalone 5G (5G NSA) are two deployment modes for 5G New Radio (NR) networks.

Standalone 5G or 5G SA is a deployment model that allows a mobile operator to build an end-to-end 5G network using 5G radio and core network components; non-standalone 5G or 5G NSA is a deployment model that has a 5G radio network that works with a 4G LTE core network (EPC – Evolved Packet Core).

The earlier generations of mobile networks primarily delivered voice calls and text messages. However, the 2G network enhancements in the late 1990s and the introduction of 3G networks in the early 2000s moved us into a world where mobile internet has become a key feature of mobile phones. 4G LTE networks have set the bar high for mobile data as LTE Advanced networks can already enable average data rates of 50 to 80 Mbps.

While 5G can take the mobile data speeds to a whole new level, it is not all about high-speed mobile broadband. 5G uses a highly flexible New Radio (NR) technology that can facilitate a wide range of use cases with varying degrees of data rate, latency and availability requirements. For example, 5G can provide connectivity to IoT devices that require very low data rates, e.g. 50 kbps, but it can also offer average mobile broadband speeds of 150-200 Mbps to a laptop.

Why do we have standalone and non-standalone 5G networks?

Deploying a 5G mobile network is a significant investment for a mobile network operator. While both 5G deployment models have their benefits, non-standalone 5G (5G NSA) can be seen as an intermediate step before introducing an end-to-end standalone 5G network (5G SA).

The use case classes for 5G New Radio (NR) consist of Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC) and Ultra-Reliable Low Latency Communication (uRLLC). eMBB, also often referred to as Extreme Mobile Broadband, is one of the most apparent 5G use cases because of the high-speed mobile broadband standard already set by 4G LTE networks.

Non-standalone 5G can utilise both 5G NR and 4G LTE networks to enable higher data rates through Dual Connectivity technology. With dual-connectivity, a 5G NR compatible mobile phone can connect with both 4G LTE and 5G NR networks to offer higher data rates to the phone users. Since non-standalone 5G can work with an existing 4G LTE mobile core network, it offers mobile operators a quick option to enter the 5G market.

The futuristic 5G use cases require standalone 5G (5G SA) that uses the cloud-native 5G mobile core network. Using frequencies in the high-band (millimetre waves) 5G standalone can take advantage of extremely low latencies to facilitate use cases where real-time communication is required. While eMBB can be enabled by non-standalone 5G, mMTC and uRLLC need a cloud-native 5G core network that is possible through standalone 5G deployment.

What is non-standalone 5G or 5G NSA?

Non-standalone 5G, also known as 5G NSA, is a type of 5G New Radio (NR) network deployment that uses a 5G radio network, Next Generation Radio Access Network (NG-RAN), alongside a 4G LTE mobile core network, Evolved Packet Core (EPC) to deliver essential 5G cellular services.

Non-standalone 5G can be seen as an early version of the full 5G NR network that offers mobile network operators a broadband-focused 5G deployment option. The average 5G data speeds are considerably higher than the average 4G speeds and good enough for streaming 4k and even 8k videos.

The improved latency in 5G NR networks also makes augmented reality (AR) and virtual reality (VR) use cases possible. The other more futuristic use cases of 5G need ultra-high reliability and ultra-low latencies, which are not possible through 5G NSA. Please check out this dedicated post on average 5G mobile broadband speeds.

Non-standalone 5G, 5G NSA requires an existing 4G LTE infrastructure to enable 5G connectivity, which means having to rely on some parts of the 4G LTE network to connect 5G devices. As a cost-effective deployment option for 5G services, NSA allows mobile operators to maximise the utilisation of their existing 4G LTE network infrastructure without investing in a 5G core network.

While 5G NSA allows mobile operators to defer the cost of buying a 5G mobile core network, it has limitations in what it can deliver. Of the three use case classes that 5G NR enables, Enhanced Mobile Broadband (eMBB) is the only one 5G NSA supports.

If the primary focus for a mobile network operator is high-speed mobile broadband, then non-standalone 5G is a quick win for them as it gives them a swift start and a great marketing opportunity. However, mMTC and uRLLC require an end-to-end 5G network which can only be achieved by deploying standalone 5G.

5G NSA requires a mobile operator to install New Radio (NR) radio base stations that are connected to the 4G LTE core network, Evolved Packet Core (EPC). EPC performs a dual role by performing core network functions for the new 5G base stations in addition to the existing 4G LTE radio base stations.

In the NSA model, the end-user side of the service where higher data is required utilises the 5G radio network capabilities whereas the control functions such as signalling still use the existing 4G LTE core network- EPC. The non-standalone 5G New Radio (NR), 5G NSA, establishes a radio network connection with both 5G NR and 4G LTE radio networks to communicate with the 4G LTE core network.

The radio network in 5G NSA works in such a way that the user-level functions, e.g. mobile data, QoS etc., utilise the 5G radio base station, gNodeB (gNB), whereas the 4G radio base station, Evolved Node B (eNodeB), manages the control functions for 5G through a concept called dual-connectivity.

A high-level diagram of a deployment model for non-standalone 5G - 5G NSA
—A high-level diagram of a deployment model for non-standalone 5G – 5G NSA—

What is standalone 5G or 5G SA?

Standalone 5G, also known as 5G SA, is a type of 5G New Radio (NR) network deployment that uses an end-to-end 5G network, including a 5G radio network, Next Generation Radio Access Network (NG-RAN) and a 5G Cloud-Native core network (5GCN) to deliver basic and advanced 5G cellular services.

The standalone 5G is an independent 5G network deployment model that allows mobile operators to launch an end-to-end 5G New Radio (NR) network. The 5G SA technology can deliver the futuristic use cases of 5G that require flexibility, availability and lower latencies in addition to high-speed data.

Standalone 5G NR makes use of the mid and high range frequency bands to enable advanced use cases that require ultra-low latencies. It can support higher frequency bands (above 6 GHz) to deliver lower latencies and higher data rates. 5G SA also supports lower frequency bands, e.g. 600 MHz and 700 MHz, to enable IoT (Internet of Things) use cases that require connectivity for billions of low-powered devices with low bit-rate needs (e.g. smart meters). Have a look at my dedicated post on 5G New Radio (NR) to learn about the frequency bands that 5G networks use.

Network slicing is a key feature enabled by standalone 5G that utilises the Service Based Architecture (SBA) of the 5G core network (5GCN) to allow mobile operators to create virtual sub-networks within the physical network. 5G networks can allocate network resources based on specific use cases with network slicing.

Standalone 5G allows the mobile operators to support Massive Machine Type Communication (mMTC) and Ultra-Reliable Low Latency Communication (uRLLC) use cases, including self-driving cars, smart cities, and many other B2B use cases in the manufacturing industry. These use cases can help digitise market verticals such as the manufacturing industry.

In standalone 5G NR, SA, both mobile network functions, including the control plane and the user plane, use the 5G network. The 5G NR base stations form part of a radio network (Next Generation Radio Access Network – NG-RAN) that works alongside a cloud-native 5G Core network (5G CN).

When a cloud-native 5G core network is employed, the connectivity for 5G devices is enabled by the 5G radio base station (gNodeB – gNB) for both user and control planes. 4G user devices can also utilise the capabilities of the 5G core network in the standalone model.

If any 4G devices require access to the LTE network through the 5G Core in standalone 5G (5G SA), instead of communicating with the regular 4G base stations (eNodeB), the 4G devices communicate with next-generation 4G base stations (ng-eNodeB). Have a look at our dedicated post on 3G, 4G and 5G base stations to learn about ng-eNodeB, eNodeB and gNodeB.

A high-level diagram of a Standalone 5G NR deployment mode - 5G SA, without an existing 4G LTE network
— A high-level diagram of a Standalone 5G NR deployment mode – 5G SA, without an existing 4G LTE network—

Is standalone 5G (SA) better than non-standalone 5G (NSA)?

Non-Standalone 5G (NSA) allows mobile operators to quickly launch basic 5G mobile broadband services using the existing 4G LTE core network; Stand-alone 5G (SA) requires a full 5G deployment, including a 5G core network to offer high-speed data, low latencies and support for billions of IoT devices.

Standalone 5G or 5G SA is the future of 5G, whereas non-standalone 5G or 5G NSA is the initial phase of 5G network deployment. Standalone 5G allows mobile operators to enable futuristic use cases where high-speed mobile broadband is just one of the use case classes.

Standalone and non-standalone deployment models are not about which one is better but more about what a mobile operator wants to achieve with 5G. Therefore, an operator’s choice of 5G network deployment needs to align with their business strategy regarding which 5G use cases they want to enable for their customers.

The Consumer customer segment is usually significant for any mobile operator, so enhanced broadband through non-stand-alone (NSA) is a great opportunity and a quick win to achieve the initial 5G penetration. Standalone 5G can give an operator the required muscle power for the large enterprise customer segment.

Depending on the operator, at least for now, NSA may be more of a consumer-focused option, whereas SA may be better placed to serve enterprise-level use cases. You may check out our dedicated post to learn what B2B vs B2C customer segments mean to a mobile operator.

Conclusion

Non-standalone (NSA) and standalone (SA) are two different modes for the deployment of 5G New Radio (NR) mobile networks. The non-standalone 5G model is a deployment model that utilises the existing 4G LTE core network, Evolved Packet Core (EPC), for enabling 5G. Standalone 5G is an end-to-end 5G network with a 5G radio network (Next Generation Radio Acces Network or NG-RAN) and a 5G Cloud-Native Core Network (5GCN).

5G NSA can work for an operator as an interim step toward 5G SA. When 5G networks reach a higher level of maturity over the next few years, we will likely see an acceleration in standalone 5G network deployments.

Here are some helpful downloads

Thank you for reading this post. I hope it helped you in developing a better understanding of cellular networks. Sometimes, we need extra support, especially when preparing for a new job, studying a new topic, or buying a new phone. Whatever you are trying to do, here are some downloads that can help you:

Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy, which explains the network nodes, e.g., BTS, MSC, GGSN etc.

Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and the challenges considering how quickly the industry evolves. The bigger picture comes from experience, which is why I’ve carefully put together a few slides to get you started in no time. So if you work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on the product overview and product roadmap.

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