In short: Public 5G is the network EE, O2, Vodafone and Three sell to consumers. Private 5G is your own dedicated network, on the same underlying technology, but ring-fenced for one organisation or community. You pick private when public falls short on coverage, capacity, latency, security, or commercial terms.
Key Takeaways
- Public 5G is shared, private 5G is dedicated — same radio standards, very different commercial and operational model
- Public 5G doesn't reach everywhere — and where it does, you have no control over capacity or priority
- Private 5G is the answer when "I just need it to work" matters more than "I just need a SIM"
In a nutshell
Same Technology, Different Networks
Public and private 5G use the same underlying standards (3GPP Release 15, 16 and 17), the same radio frequencies (with different licensing), and largely the same equipment vendors. A 5G phone doesn't know — and doesn't care — whether it's connected to a public mobile operator or a private network. The radio is the same.
The difference is who owns the network, who's allowed on it, and what guarantees they get.
Public 5G: What You Get
Public 5G is sold by mobile network operators — in the UK that's EE, O2, Three, Vodafone, plus a long tail of MVNOs that resell their service. You buy a SIM, you connect anywhere the operator has built coverage, and you share the network with millions of other customers.
The good:
- Cheap per device (SIM-only deals from £10/month)
- Works on most devices
- Coverage in most cities and along motorways
- No infrastructure to build
The not-so-good:
- Coverage is patchy in rural areas, indoors in older buildings, and in basement levels
- Capacity is shared — speed drops in busy areas at busy times
- You can't reserve bandwidth or prioritise traffic
- No SLA — if the network breaks, you wait
- Devices are visible to the operator (not always desirable for sensitive workloads)
For most consumer use, public 5G is fine. It's when you're trying to do something specific — guarantee uptime, cover a specific site, run mission-critical equipment — that the limits start to bite.
Private 5G: What You Get
Private 5G is a 5G network built for a single organisation, community, or venue. It uses dedicated spectrum (in the UK, typically Ofcom Shared Access Licence spectrum at 3.8–4.2 GHz), dedicated equipment, and a dedicated core network. Only devices with SIMs you've authorised can connect.
The good:
- Coverage exactly where you need it — including places public networks don't reach
- Dedicated capacity — no degradation under load
- Predictable, low latency suitable for autonomous systems and real-time control
- SIM-based authentication for fleets of devices
- You control who connects, what data leaves the site, and how bandwidth is allocated
- SLA-backed by the provider
The trade-offs:
- Higher cost than a single SIM (though when you're connecting hundreds of devices, the per-device cost becomes very competitive)
- Coverage is local — you don't get a free roam to Manchester
- Requires either in-house expertise or a managed service provider
Five Scenarios Where Private Wins
Here's when we see customers move from "we'll just use public 5G" to "we need our own network":
1. The site doesn't have public 5G coverage
The most common driver. Welsh valleys, remote farms, holiday parks, much of rural Scotland — public mobile operators haven't built 5G there and won't anytime soon. A private network is the only option.
2. The site has coverage but it's congested
City centre venues, busy ports, large events. Public 5G is technically there, but in busy periods you can't get useful throughput. A private network ring-fences capacity that doesn't degrade.
3. You need predictable latency
Autonomous vehicles, robotics, AR maintenance, push-to-talk voice for emergency services. Public networks can't guarantee sub-10ms latency at scale. Private networks can.
4. You're running fleets of devices that need to be secure
A factory with 5,000 IoT sensors. A logistics yard with 200 connected forklifts. A care home network with telecare devices. SIM-based authentication scales better and is structurally more secure than passwords.
5. The data needs to stay on-site
Defence, healthcare, sensitive industrial control systems. With a private network, you can keep traffic local and route only what needs to go off-site through a controlled internet break-out.
Five Scenarios Where Public Wins
Equally honest: there are situations where private 5G is the wrong answer.
- A handful of phones for a small office in central London — buy SIMs.
- A workforce that travels constantly — public mobile + good roaming agreements.
- Highly intermittent connectivity needs (a few hours a week) — pay-as-you-go SIMs.
- Use cases where the data you're carrying is truly low-value and the cost of running your own infrastructure isn't justified — public 5G is fine.
The Hybrid Pattern
In real deployments, most organisations run both. Aerix customers, for example, often have:
- A private 5G network covering their primary site, providing dedicated broadband and operational connectivity
- Public 5G SIMs in vehicles, mobile workers' phones, and equipment that travels off-site
The private network handles the high-value, predictable, location-bound use cases. Public networks handle the low-value, mobile, opportunistic ones. They co-exist on the same devices via dual-SIM or SIM swap.
Quick Comparison
| Public 5G | Private 5G | |
|---|---|---|
| Owner | Mobile operator (EE, O2, Vodafone, Three) | You (or your provider) |
| Coverage | Where the operator built it | Where you need it |
| Capacity | Shared, can be congested | Dedicated, predictable |
| Latency | Variable | Consistent, low |
| Security | Operator-managed | You control authentication |
| Cost | Per-SIM subscription | Network subscription or capex |
| Best for | Mobile workers, low-density use | Site-bound, high-density, mission-critical |
If you're weighing public vs private for a specific site, get in touch — we'll tell you which is the right fit, even if it's not us. Or read our private 5G architecture explainer to see what's involved in deploying a private network.