The term 5G has crept into our daily lives for some years now, but Not all 5G that we see on the mobile screen is the same or offers the same capabilitiesWith technical terms like 5G NSA, 5G SA, or DSS, it's easy to get lost, and in the end, many users are unclear whether they are enjoying "full 5G" or a kind of souped-up 4G.
To clear up the confusion, it's important to understand that the 5G standard has been designed in several phases, combining elements of the 4G network with the new 5G components. The key lies in how the core network, antennas, and your mobile device are organized to deliver higher speeds, lower latency, and new features such as network slicing and massive IoT.Let's break down, calmly and with examples, what 5G SA and 5G NSA are, their real differences, and where we stand in Spain and the rest of the world.
How 5G has been defined: phases, releases and network types
The 3GPP organization, responsible for standardizing mobile networks, decided that the jump to 5G would not be all at once, but in several stages. It divided the transition into a first phase of 5G supported by 4G (5G NSA) and a second phase with pure 5G from beginning to end (5G SA), defined in different Releases of their standard.
The so-called 3GPP Release 15 is what brings 5G NSA (Non-Standalone) to life, a mode in which The network relies on the 4G EPC core but adds a new 5G NR radio to increase capacity and speed. In other words, the existing 4G infrastructure is used to its fullest potential, adding 5G blocks where they are most needed.
The next major stage comes with Release 16, which includes the 5G SA (Standalone) model. In this case, Both the radio and core network components are 100% 5G: NR is used for access and 5G Core (5GC) is used at the heart of the networkThis allows for the deployment of all the advanced features planned for the new generation.
Both modes, NSA and SA, are recognized by 3GPP as genuine 5G, but The most groundbreaking advantages—minimal latency, advanced network slicing, large-scale IoT, and ultra-reliable communications—are only fully unlocked with 5G SAThat's why it's often said that NSA is a transition phase and SA is the "complete" 5G.
Key elements of a mobile network: core, radio and mobile
To understand why these two types of 5G exist, we need to see what parts make up a modern mobile network. At a very simplified level, we have three elements: the network core, the antenna system, and the user devices..
The network core is the brain of the system. In 4G it is called EPC (Evolved Packet Core) and in 5G, 5GC. Their job is to decide which mobile phones can connect, apply tariffs and speed limits, manage mobility between antennas, and control the priority and quality of each communication.In 4G this core usually operates on dedicated and centralized hardware, while in 5G it is virtualized, distributed and cloud-ready.
The antenna system is what's known as a RAN (Radio Access Network). In 4G we're talking about LTE, and in 5G about NR (New Radio). NR antennas define how the signal is modulated, what bandwidth is used, what frequency, how the subcarriers are distributed, or how techniques such as Massive MIMO are applied.This allows more data to be transmitted through the air with the same amount of spectrum.
The third element is user equipment (UE). This includes smartphones, but also... Laptops with 5G modems, connected vehicles, industrial sensors, robots, household appliances, or video cameras that connect directly to the mobile networkWithout a 5G-compatible device, it doesn't matter if the operator has deployed the best network in the world.
The combination of these three parts (core, RAN and devices) is what gives rise to the different possible architectures: pure 4G networks, mixed 4G/5G NSA networks and 5G SA networks with all components already in the new generation.
What is 5G NSA: the first step built on 4G
5G NSA (Non-Standalone) is the architecture that most operators have used to launch 5G quickly and without rebuilding all their networks at once. Here the core remains 4G EPC, but a 5G NR carrier is added as an extra channel for data traffic.
In this scenario, the mobile maintains a primary 4G connection (which handles the control plane, i.e., signaling and connection management) and It adds an additional 5G NR carrier for the user plane, which is where your internet, video, online gaming, or application data travels.The 4G core remains in command, but benefits from the extra capacity of the 5G radio.
This idea is based on something that already existed in LTE Advanced: Carrier Aggregation (CA). In 4G+ your mobile can combine several LTE carriers to increase its capacity; with 5G NSA, a primary LTE carrier and a secondary NR carrier are combined., which boosts the maximum speed available when using widebands such as 3,6-3,7 GHz.
With 5G NSA, under good conditions, users can achieve download speeds close to 2 Gbps, reduce latency to around 10 ms, and obtain a More stable connection even while moving or in crowded areasthanks to technologies like Massive MIMO and the use of more spectrum.
In Spain, the first 5G deployment was precisely NSA: Vodafone turned on its network in the 3,7 GHz band in 2019. It is a high-capacity band but has worse indoor penetration and a shorter range than lower bands such as 700 MHz.Therefore, it is especially designed for cities and areas with high data demand.
How the spectrum fits together: 3,7 GHz and 700 MHz bands
For 5G to work, it's not enough to have new antennas: radio spectrum is needed. Both 5G NSA and 5G SA use bands specifically allocated to this technology, but each frequency band has its compromises..
In the first phase, deployments have relied mainly on the 3,5-3,7 GHz band, which offers channel widths of up to 100 MHz. The wider the channel, the higher the raw speed that can be achieved, but at the cost of shorter coverage and worse penetration into buildings., something we have seen in the first urban deployments of Vodafone, Telefónica or other European operators.
The 700 MHz band, released with the second Digital Dividend, is the other major pillar of 5G. By operating at lower frequencies, it allows for expanded coverage in rural areas and improved indoor signal strength.Although maximum speeds per carrier are lower than at 3,5 GHz, the combination of both bands (low for coverage, high for capacity) is the ideal recipe for a balanced 5G network.
Spanish operators have been participating in auctions to divide up these frequencies, with different strategic moves. Telefónica, Vodafone and Orange have bid for 700 MHz, almost forced to do so in order not to be left behind in the future SA deploymentMeanwhile, MásMóvil has found itself in the position of having to decide whether to invest heavily or continue depending on wholesale agreements with third parties, as it already does in 4G.
Without those low frequencies, an operator with its own network would find it very difficult to offer truly competitive 5G coverage and would be forced to Sign access agreements with other companies to guarantee service throughout the country, with the advantages and limitations that this entails in terms of costs and control.
What is 5G SA: autonomous and “full” 5G
5G SA (Standalone) is the next logical step: a network in which both the core and the radio are fully 5G and do not depend on 4G at allHere the need to maintain an LTE carrier as an anchor disappears and the mobile can connect only to NR carriers, even adding several 5G bands at the same time.
In 5G SA, the 5GC core assumes full control of the network. This core is cloud-native, based on virtualization and containers, can be deployed in a distributed manner near the antennas (edge computing), and scale according to demand.This allows for even lower latency and computing resources closer to the user.
One of the great advantages of 5G SA is network slicing. Thanks to this technique, multiple independent virtual networks can be created on the same physical infrastructure, each with its own guaranteed bandwidth, latency, priority, and reliability level.In other words, we can reserve exclusive "pieces" of the network for specific clients or services.
This is key for use cases such as connected vehicles, emergencies, industrial automation, or real-time healthcare. Imagine a self-driving car that needs minimal latency and ultra reliability, or a camera that streams live 4K video from a factoryEach user can go on a different "slice" optimized for their needs, without overlapping with other users.
5G SA also multiplies the capacity for massive IoT (mMTC). The network can support a much higher density of connected devices in a small area, which is crucial for smart cities full of sensors, hyper-automated manufacturing plants, or networks of connected household meters and devices..
Furthermore, by being able to place parts of the core near the antennas using edge computing, Data round-trip times are reduced, enabling applications such as remote surgery, real-time robot control, or motion sickness-free augmented reality experiences.All of this is practically impossible with the latency inherited from a traditional 4G network.
Practical differences between 5G SA and 5G NSA
When it comes down to it, for the average user it may seem that “5G is 5G” and little else. But At the infrastructure and capabilities level, the difference between SA and NSA is substantial., both for operators and for companies that want to set up advanced services.
In 5G NSA, as we have seen, The network relies on the 4G EPC core and adds NR as a data channel, thus inheriting some latency, limitations in network segmentation, and a less flexible architecture.It's a very useful upgrade in speed and capacity, but there's room for improvement in terms of critical applications and fine-tuning the quality of service.
In 5G SA, on the other hand, the 5GC core allows for the full enabling of features such as URLLC (Ultra-Reliable Low Latency Communications) or mMTC. Low latency is no longer just laboratory data; it's becoming something that can be guaranteed for certain services., something essential for autonomous vehicles, advanced automation or demanding cloud gaming.
Scalability also changes a lot. With SA, being a cloud-native architecture, the operator can easily scale network functions, deploy new services in specific areas, and dynamically adjust resources.In NSA, tied to the EPC 4G, that flexibility is less and forces you to think more in terms of hardware upgrades and fixed configurations.
For all these reasons, 5G NSA is often considered a very useful transitional technology to quickly begin offering speed and capacity improvements, but The ultimate goal of the operators is to progressively migrate to 5G SA to deploy all the possibilities of the fifth generation.
Mobile compatibility and transition between NSA and SA
To take advantage of any of these 5G modes, there are three basic requirements: a tariff and operator that offers 5G, real 5G coverage in the area, and a 5G compatible deviceSo far, nothing surprising, but with SA and NSA, another layer of complexity is added.
Operators have made efforts to ensure that the change between NSA and SA is invisible to the user. When the time comes, the phone will connect to one architecture or the other depending on what is available, without you having to do anything.But that will only be possible if the phone's modem supports both modes.
In the early days of 5G, many smartphones were only compatible with NSA. Some early models with modems like the Qualcomm X50 or certain Exynos 5G could barely work with non-standalone networksThis means that they will not be able to take advantage of 5G SA if the operator activates it in their city.
Other devices, such as those that integrate new generation modems (for example, Qualcomm X55 and later, many current MediaTek chips or Huawei's Balong 5000), Yes, they offer compatibility with NSA and SA networks, ensuring that they will remain valid as the network migrates to standalone 5G.When buying a 5G mobile phone, this detail makes the difference between having a "half-baked" 5G phone or one that's future-proof.
Furthermore, in some commercial SA deployments, such as those called 5G+ by some Spanish operators, You need an updated SIM card that is compatible with the new security and authentication features of the 5GC core.The same chip you've had for years isn't always enough to take full advantage of the potential of standalone 5G.
What is 5G DSS and why is it still important?
Another term that often appears alongside SA and NSA is DSS (Dynamic Spectrum Sharing). This is a technique that allows dynamic sharing of the same frequency band between 4G and 5G NRalternating thousands of times per second between both technologies depending on demand.
Thanks to the software-defined radio (SDR) equipment installed in many modern 4G antennas, Operators can update their base stations via software to broadcast both LTE and NR over the same carrierwithout having to physically replace all the hardware at once.
DSS is very useful for starting the migration to 5G without leaving 4G users on that band stranded. As long as there are older mobile phones that only understand LTE, the network can continue to serve them, while also providing service to 5G devices using the same frequency.However, there is a price to pay: by combining both technologies, some efficiency is lost and the available practical bandwidth is reduced.
In practice, when you are connected to a 5G NSA with DSS, your mobile is simultaneously using a 4G LTE signal (for control) and a 5G NR signal (for data) on that same shared band. The NR carrier in this case is usually limited to the original 4G bandwidth and part of the spectrum is consumed in the DSS management itself.Therefore, speed improvements may be modest or even non-existent compared to a good 4G connection.
Despite its limitations, DSS has allowed operators such as Telefónica or Orange to quickly extend “5G” coverage, inflating the map of areas with 5G even though the practical improvement is small. And most likely, DSS will be with us for many years, even when 5G SA becomes more widespread., to continue supporting older generation terminals on certain bands.
5G NSA and SA rollout in Spain and worldwide
In Spain, the first commercial 5G network was NSA, launched by Vodafone in 2019, with initial coverage in several large cities and priority use of the 3,7 GHz band. Later, Telefónica and Orange joined in, relying heavily on DSS to rapidly expand the “5G” footprint without completely changing the infrastructure., while MásMóvil was progressing more cautiously.
At a commercial level, the discourse of the operators has been somewhat different. Orange, for example, expressed support for waiting for 5G SA before discussing a “full” rollout., and launched its 5G+ service (based on SA) first in cities such as Madrid, Barcelona, Valencia or Seville, while planning expansion to the rest of the country.
Movistar has announced plans to to complete the deployment of its 5G SA core in the near futureVodafone has set dates for activating its own standalone network. In all cases, the idea is to coexist with NSA and SA for a while, gradually migrating services and customers to the more advanced architecture.
In the rest of the world, the pattern has been similar: the first deployments have almost always been based on 5G NSA. Switzerland, Finland, the United Kingdom, South Korea, the United States, Uruguay, and South Africa launched 5G on top of 4G networks, adding NR to increase capacity and speed, with a second phase of SA deployments planned as the 5GC standard matured.
South Korea is one of the most prominent examples: there, operators such as SK Telecom, KT Corporation or LG U+ have deployed tens of thousands of 5G base stations, a large part of them in the 3,5 GHz band. The density of antennas in major Korean cities is enormous, enabling very high speeds and a very consistent user experience., although the path towards a massive SA continues its course.
Europe is also making progress: Countries like Germany and France have already held spectrum auctions for 5G and are working on networks that combine NSA, DSS and, progressively, SAThe situation is very heterogeneous, but the trend is clear: first, the existing infrastructure (4G + NSA) is used to its fullest potential, and then the complete leap to autonomous 5G is made.
One striking aspect of the Spanish case is that, in some releases, Access to 5G has not resulted in any extra cost to the tariff, while in other European markets monthly surcharges have been levied for the 5G service.This has made it easier for many users to jump on the new generation without thinking too much about it, even if they don't yet see all its advantages.
What improvements will you notice and what's coming next
With current 5G NSA networks, the most obvious improvement for the user is the increase in download speed, especially when using bands with a lot of spectrum dedicated to 5G. A slight reduction in latency and greater stability are also achieved when the network is heavily loaded.This is noticeable in streaming, heavy downloads, or online games.
However, in day-to-day use, and while applications are still not fully utilizing the new capabilities, The user experience can be quite similar to that obtained with a good 4G+ connection.This has led to many users having 5G on their mobile phone icon but not experiencing as dramatic a leap as they did when going from 3G to 4G.
When 5G SA becomes more widespread, we will start to see more differences. In addition to faster upload speeds, lower latency, and better energy efficiency in mobile devices, services that depend precisely on these characteristics will be deployed.: connected vehicles with critical communications, remotely controlled industrial robots, real-time augmented reality, or private 5G networks for businesses and factories.
The very design of the 5GC, distributed at the edge, will allow computing services to be brought closer to the user. This opens the door to experiences such as cloud gaming with minimal response times or collaborative virtual reality applications.where the game or content server is practically "around the corner" from a network perspective.
This entire universe of applications will arrive gradually, and in the meantime, 5G networks will continue to coexist with 4G, relying on NSA, DSS and agreements between operators to share infrastructure and costsThe transition doesn't happen in a day, but the direction is set.
Understanding what 5G SA and 5G NSA are, how they rely on the core and radio, the role of bands like 700 and 3,7 GHz, and why network slicing and massive IoT depend on autonomous 5G helps to make sense of all the acronyms. Ultimately, what we see today as a new icon on the signal bar is just the tip of the iceberg of a much larger network. deep transformation of mobile networks, which will gradually unfold its effects in the coming years.
