LoRa, Wi-Fi or 4G: choosing how your field sensors connect
Range, power use and running costs differ a lot between the three. Here's how we decide which one a site needs.
Sensors notice, events carry the news, AI decides. Together they're changing how farms, factories and cities respond in real time.
A sensor notices something. An event carries the news. A model decides what it means. A machine acts. That loop, running thousands of times a second across farms, factories and cities, is quietly changing how the physical world responds to us.
Each of these technologies is useful on its own. The Internet of Things gives us measurements from places people can't watch all day. Event-driven architecture moves information the moment something happens instead of waiting for someone to ask. Artificial intelligence turns raw signals into judgements. Put them together and you get systems that don't just report on the world but react to it, often before a person would even have noticed.
In this post we look at what each piece contributes, why the combination matters, where it is already making a difference, and what makes it hard to get right.
The easiest way to understand the combination is as a loop with four steps.
The action changes the world, the sensors notice, and the loop runs again. The more often the loop runs and the faster each step is, the more responsive the system becomes.
IoT is the part that touches the physical world. A connected device is usually a sensor or actuator, a small processor, a power source and a radio. Ten years ago each of those was expensive and power-hungry. Today a device that measures, thinks a little and reports over a long-range radio can run for years on a battery or indefinitely on a small solar panel.
That change in cost and power is what lets us measure things that were never worth measuring before: the moisture in every bed of a greenhouse rather than one, the temperature of every pallet rather than every truck, the vibration of every pump rather than the one that failed last year.
But more sensors mean more data, and most of that data is boring. A soil reading that hasn't changed in an hour tells you nothing new. That's where the next piece comes in.
Traditional software tends to work by asking. A dashboard queries a database every few minutes; a report runs every night. That works when the world changes slowly. It struggles when a cold-store door is left open or a pump starts to vibrate in a new way, because the answer is only as fresh as the last time someone asked.
An event-driven system flips this around. Instead of waiting to be asked, the part that notices a change announces it. Other parts of the system subscribe to the kinds of events they care about and react when one arrives. An event is just a small, structured fact about something that happened:
{
"type": "soil.moisture.low",
"site": "greenhouse-2",
"zone": "C",
"value": 31.5,
"unit": "%",
"threshold": 35,
"time": "2026-10-07T06:42:10+05:30"
}
A message broker sits in the middle and delivers events to whoever has subscribed. In IoT, MQTT is the most common choice for getting events off devices because it is lightweight and copes well with unreliable networks. Further back, platforms such as Apache Kafka store large streams of events so many services can process them and replay them later.
Three properties make this model a natural fit for the physical world:
Events tell you that something changed. AI helps decide whether it matters and what to do. Simple rules go a long way ("if moisture drops below 35%, open the valve"), but rules struggle with the messy patterns of the real world. Some examples of what models add:
Where the model runs matters. Edge AI runs small models on the device or gateway itself, which keeps working when the connection drops, responds in milliseconds and avoids sending raw data off site. Cloud AI has far more computing power and sees data from every site, so it is better for heavier models and for learning from patterns across many locations. Most real systems use both: quick decisions at the edge, deeper analysis and model training in the cloud.
Soil, weather and crop sensors publish readings; models forecast water needs and disease risk; irrigation and ventilation respond automatically. Farmers spend less time walking fields to check and more time acting on what matters. This is the problem our own platform, Viva, was built for.
Vibration, temperature and current sensors on machines feed models that spot the early signs of wear. Maintenance moves from fixed schedules, or waiting for a breakdown, to fixing things when the data says they need it.
Trackers report location and temperature as events. If a refrigerated container starts warming, the system can alert the driver, notify the receiver and rebook the shipment while the goods are still safe.
Buildings adjust cooling to how many people are actually present. Grids balance rooftop solar, batteries and demand in real time instead of relying only on large power stations.
Water networks detect leaks from pressure changes, streetlights dim when roads are empty, and waste collection follows how full bins actually are rather than a fixed route.
Wearables and home monitors can flag worrying changes in a patient's readings to a care team, helping people stay safely at home for longer.
The examples differ, but the shift underneath them is the same in three ways.
People don't disappear from this picture. The best systems take over the routine reactions and hand people the decisions that need experience, context or accountability.
None of this is automatic. The projects that succeed take these challenges seriously from the start.
You don't need to rebuild everything at once. The approach we recommend to clients is deliberately small: