Private mobile networks have been around for many years, as we noted in a paper published back in 2021 (still worth reading for an overview of that market). They’ve been used by utility companies, for offshore infrastructure, and in a wide range of public safety networks, to give just a few examples. All the term really means is that they are closed and that users of public land mobile networks cannot readily access them.
However, in recent years, the term has become more aligned with developments in 5G specifically, rather than mobile in general. That’s because 5G offers enhanced capabilities that can enable new levels of low latency and coverage performance. But because latency is a factor of distance, this also creates a need to shift processing assets from the core of the network closer to the source of demand. We’ll explore this in more detail below.
While Mobile Network Operators (MNOs) are transforming their networks to enable what is known as ‘edge’ processing to support advanced 5G applications, others have recognised that these capabilities can also be provided by dedicated private networks, optimised exclusively for specific applications.
As a result, there has been strong interest from the private sector for non-public mobile networks (NPNs), with a surge in deployments recorded globally by industry associations such as the Global Mobile Suppliers Association (the GSA)[1], which has counted nearly 1500 NPN deployments globally.
What is an NPN – and why are they of interest today?
A public mobile network typically covers as much of an entire country as possible and mobile subscribers can access such networks because of the technology behind the SIMs (physical or otherwise) included in mobile devices. These allow devices to register and obtain authorisation to use mobile services – in the home network, or in one that is visited when travelling (roaming).
A private mobile network, on the other hand, is one that is (usually) closed, and different permissions are applied to restrict access, although SIMs of one form or another are still required. The term NPN has become the contemporary term used to describe such networks and to differentiate them from conventional mobile networks, regardless of the purpose for which they are deployed.
Such a network will have its own radio access components and may have its own core for control. Different models of NPN have been proposed, some of which have a dedicated core, while others use a hybrid model, with a core shared between different such NPNs.
Historically, such networks have largely been closed to unauthorised users or devices, because they have served critical infrastructure. For example, many railway network operators have built and maintained their own NPN to provide mobile connectivity for essential railway communications.
Similarly, utility companies have used them to connect different wireless devices in power stations, or across transmission grids. Likewise, blue light services also run their own dedicated networks.
Today, there is growing interest in NPNs because mobile technology has evolved to enable new levels of performance. While 4G, 3G and 2G were essentially networks dedicated to a single set of services — mobile voice, messaging and data connectivity — 5G supports a growing number of other kinds of services, that can meet the needs of demanding applications.
In particular, 5G offers a range of services that are optimised for extremely dense connectivity — for example, for thousands of IoT devices in a small area — and also for applications that demand real-time processing.
In the latter case, this means that delays in communication from the servers that process the applications cannot be tolerated. Delay is caused largely by a factor called latency, which is a function of the distance between the device requesting an action or service and the servers that provide the appropriate responses and commands.
In public networks, such latency can sometimes be noticed when using video, or during a voice call. However, users can tolerate this, because they can generally be patient, or keep retrying until they succeed. An application that collects an essential input from a sensor and needs to make an immediate response does not have that luxury. So, until 5G, many such applications depended on costly wired infrastructure, which connected devices and servers locally.
Now, with edge computing (which was possible before 5G, but not generally adopted), the situation has changed. A local 5G network, optimised for low latency communications, for example, can provide the micro-second responses that critical applications need – and enable businesses to avoid the cost of installing complex local cabling, for example.
How do you build one?
All mobile networks consist of a few basic elements. First, there’s the radio network – the base stations that provide connectivity to mobile devices, such as smartphones. Second, there is backhaul transport – connectivity to each base station that aggregates the signalling and data required for each device. This can be physical, or microwave wireless technology can also be used.
Finally, there’s the core. This is the set of platforms and servers that handle services, user admission and control, data processing – and which enable access to other networks, such as the internet, other operators, or CDNs. There is a bit more — billing and operational support — but with the radio, transport and core, you’ve basically got all of the building blocks in place.
In a classical network, the radio network is highly distributed, providing the cells of coverage with which we are so familiar. Meanwhile, all of the relevant session and user data is sent to the core for verification and processing. That might be over some distance – hundreds of kilometres, in practice. This is what creates the latency problem to which we have referred. For time sensitive applications, that really matters.
So, by pushing the processing systems out to the edge of the network, where it’s needed and where the users are, latency can be significantly reduced. But, there’s one part of the picture missing. Spectrum.
Radio spectrum for NPNs
All mobile networks use radio signals for connectivity to the physical part of the network. These use licensed bands that are controlled internationally to ensure they can be used safely and do not interfere with other forms of radio or network. Generically, the wavebands are referred to as radio spectrum, and each generation of mobile technology uses specific wavebands that have different levels of capacity and reach.
While these are allocated internationally by an agency of the UN, national governments control how these can be accessed by relevant stakeholders, typically through the auspices of a relevant regulator – like the Swiss Ofcom, for example.
In practice, this means that governments (and their regulators) have typically reserved the relevant bands for MNOs that seek to deliver national coverage. So, if spectrum is controlled nationally and internationally, how can we build private networks that depend on spectrum within the nominated wavebands for, for example 5G?
Well, some has always been retained for special purposes and not available to the public – for the police, railway operators, the military and others. However, recognising that the capabilities that 5G enables would be of interest to specialist players from industrial and other sectors, some national regulators have decided on a change of policy for 5G spectrum allocation.
They have reserved portions of the available spectrum specifically for NPNs – enabling private actors to obtain the necessary rights to use radio frequencies, but without the obligation to deliver nationwide coverage to the public.
That’s because an NPN is, by definition, for a limited area – and the applications for which they are now intended are, generally speaking, orientated more towards highly localised deployments.
Applications and use cases for NPNs
As has already been noted, 5G is designed to support many kinds of applications, some of which are general in nature, such as classical mobile broadband and voice, while others are much more specialised, such as those requiring low-latency performance, or very high-density connectivity in a specific area. It is applications of this nature for which NPNs are most relevant.
The creators of 5G envisaged that it could serve factories, autonomous vehicles, e-Health and other applications. While MNOs can offer advanced 5G for such cases, NPNs can offer a more cost-effective and right-sized alternative. For example, a port might wish to build a network to service critical functions within its zone of operations (think driverless cranes for handling cargo and the like, as well as secure interchange of customs information, and vast numbers of connected devices in containers). Similarly, a hospital, a sports stadium, or a complex logistics centre with autonomous robots might all benefit from a dedicated NPN.
And, removing wires means that all sorts of things can be connected to the network. Want to build a complete digital twin of a factory? That’s a lot of data to capture and update. Do you need to use Building Information Modelling (BIM) for a construction site and run it locally? Build an NPN and tear it down again when the building has been completed. Want real-time information from across the factory floor with process optimisation for the production line, in real-time?
There are, literally, thousands of such use cases and many stakeholders are exploring how they can gain access to the capabilities that NPNs offer – and going it alone or working with a specialist provider and not a traditional MNOs are just two of the options many are considering.
Telecom26 – how do we help?
Many companies and organisations recognise the potential that NPNs can offer. They — not MNOs — are best placed to understand the kinds of performance that they need to achieve within the NPN. However, translating business KPIs into network KPIs to ensure that the NPN delivers is a different matter.
That’s where we come in. We have the experience and technical know-how to help any organisation deploy the right kind of NPN – optimised to meet business and organisational goals. Of course, large MNOs may also help – but they may only be focused on multi-national corporations, not the needs of smaller businesses.
Where spectrum is available from the regulator, we can help you secure the frequency you need for the intended location. We can provide the radio, transport and core — and we can even help determine how you enable access to your network — together with our SIMs for local device connectivity, protected by our advanced security.
Best of all, we take care of the mobility part, while you focus on the outcomes you seek from the NPN. It’s a partnership that blends our expertise with yours, bringing NPNs to any organisation that needs them. Your network, how you want it – delivered and managed by us with our connectivity.
Why not talk to us and see how we can help?
[1] Private Mobile Networks, September 2024, GSA
