IoT connectivity in the factory is the network layer linking sensors, machines and control systems to a data-collecting platform — its choice (wired, Wi-Fi, private 5G, LPWAN) and communication protocol (OPC UA, MQTT, Modbus) need to follow the specific requirements of a production floor, not a single universal pattern copied across plants.
Quick Overview
What you’ll learn:
- Why one network architecture doesn’t work for every production floor
- How to choose between Wi-Fi, private 5G and wired networks
- Which communication protocols dominate industrial IoT and what each is for
- Which architectural mistakes cost companies the most after rollout
Who this article is for:
- Automation and industrial network engineers
- Project managers running IoT rollouts in production
- Operations directors evaluating factory floor modernisation costs
Reading time: 6 minutes
IoT connectivity in the factory: why network architecture decides rollout success
The most common mistake in industrial IoT rollouts is treating the network as secondary to sensors and software — but it’s the network architecture that determines whether data reaches the system in real time, reliably enough, and without interference from existing industrial infrastructure (motors, frequency converters), which generates real electromagnetic interference that affects wireless networks.
Ericsson’s recurring Mobility Report documents growing adoption of private 5G networks in industrial settings as an answer to classic Wi-Fi’s limitations — deterministic latency, isolation from public network infrastructure, and better handling of mobile devices (such as autonomous guided vehicles) moving between zones on the floor.
Wi-Fi, private 5G or a wired network: how to choose
| Criterion | Wi-Fi 6 | Private 5G | Wired (Ethernet/PROFINET) |
|---|---|---|---|
| Device mobility | Good within access point range | Very good, seamless handoff between zones | None — stationary devices |
| Resistance to electromagnetic interference | Moderate | High | Very high |
| Rollout cost | Low-medium | High (own radio infrastructure) | Medium-high (cabling) |
| Typical use case | Stationary sensors, operator panels | AGVs, mobile robots, large floors | Real-time control, critical lines |
The decision is rarely binary — most modern plants combine all three layers: a wired network for real-time critical control, Wi-Fi or 5G for mobile devices and sensors spread over a large area.
Communication protocols: which does what
Three protocols dominate industrial IoT, each with a different purpose: OPC UA is the standard for exchanging data between machines and upstream systems (SCADA, MES), designed with security and semantic data modelling in mind, and works well as an integration layer between different equipment vendors. MQTT is a lightweight publish-subscribe protocol optimised for low bandwidth and a large number of simultaneously connected sensors — dominant in cloud and edge computing scenarios where minimising network traffic matters most. Modbus, despite being the oldest of the three, is still common in older machines as a native protocol — new rollouts often need a gateway translating Modbus into OPC UA or MQTT instead of replacing an entire fleet of machinery.
Architectural mistakes that cost the most after rollout
The most expensive mistake is designing the network for the current number of sensors without headroom for future expansion — companies regularly discover a year after rollout that adding another production line with new sensors requires rebuilding the entire network infrastructure, not just connecting new devices. A second common mistake is ignoring network segmentation — an IoT network connected directly to the office network with no dedicated zones (VLANs, an industrial firewall) creates a real security risk, where an attack on an office computer could reach critical production control systems.
Read Also
- Industrial IoT: A Complete Guide to IoT in Manufacturing — a broader overview of IoT applications in production
- Impact of the Internet of Things (IoT) on Industry 4.0 — how IoT is transforming the manufacturing sector
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Designing IoT connectivity for an industrial environment is best started with the training 5G and IoT: The Synergy of Future Technologies. Check the programme and sign up to develop your skills with EITT experts.
Frequently Asked Questions (FAQ)
Is it worth investing in private 5G right away, or should we start with Wi-Fi?
It depends on scale and mobility requirements. For smaller floors with mostly stationary sensors, Wi-Fi 6 is often enough at a lower rollout cost. Private 5G pays off in large plants with many mobile devices (AGVs, robots) and high reliability requirements for the connection.
Do OPC UA and MQTT exclude each other?
No, they often work together in the same architecture — OPC UA as the integration layer between machines and upstream systems at the floor level, MQTT as the transport protocol for data going to the cloud or analytics systems, where low bandwidth and a large number of connections matter most.
What should you do with older machines that use Modbus?
The most common solution is a protocol gateway translating Modbus into OPC UA or MQTT — this lets you integrate an older fleet of machinery with a modern IoT architecture without an expensive replacement of production equipment that still works correctly mechanically.
How significant is the security risk of connecting machines to an IoT network?
Real, if the IoT network isn’t separated from the office network and the internet by proper segmentation. Without dedicated zones (VLANs, an industrial firewall), an attack on any office computer could in theory reach production control systems — which is why network segmentation is part of the design, not an optional extra.