LoRaWAN is a low-power, wide-area radio standard designed for devices that send small amounts of data, reliably, over long distances. For temperature monitoring that is exactly the job: a reading every few minutes, from a unit that may be several walls and floors away from the nearest gateway, from a sensor nobody wants to rewire or recharge.
It is not a new or experimental choice. There are 1,900+ LoRaWAN node sensors and 330+ LoRaWAN gateways connected to the Sematics platform we install and support. This page explains what LoRaWAN does well, where its limits are, and why it matters for the record you show an inspector.
What LoRaWAN is
LoRa is the radio technique: a slow, narrow signal that a gateway can pick out even when it is very weak. LoRaWAN is the network protocol on top, which handles how sensors join the network, how their messages are encrypted (AES-128) and how a gateway passes them on to the platform.
The trade-off is deliberate. LoRaWAN cannot stream video or carry large files, but a temperature reading is a few bytes, so speed is not the point. What you get in return is range, the ability to get through walls and racking, and very low power use.
| Control | LoRaWAN | Wi-Fi | Bluetooth |
|---|---|---|---|
| Covers a building or more from one receiver | ✓ | · | · |
| Runs for years on small batteries | ✓ | · | ✓ |
| Works without your site IT network | ✓ | · | ✓ |
| Built for small, frequent readings | ✓ | · | ✓ |
General properties of each technology, not a test result.
Range: fewer gateways, fewer blind spots
Our Node+ sensors typically reach around 1 km inside built environments and up to 20 km in clear line of sight with an elevated antenna. Real range depends on the site: concrete, steel racking, cold-room panels and machinery all absorb signal. That is why we survey before we install rather than quote a distance.
In practice the range means a warehouse, a multi-building hospital site or a depot with an outdoor yard can often be covered by a handful of gateways. Each one can handle up to 2,000 sensors. Fewer gateways means fewer things to power, mount and maintain, and fewer places for the network to fail.
Power: years on two AA batteries
LoRaWAN sensors spend most of their time asleep. They wake, take a reading, send it and go back to sleep. The network can also tell a sensor to use less transmit power when it has a strong signal. A Node+ runs for up to 4 years on two replaceable AA lithium cells at 5-minute logging, and 8 years or more at 10 to 15 minutes.
That matters for maintenance. Battery changes can be planned alongside annual calibration rather than chased one sensor at a time, and the platform shows each sensor's battery level, so a change can be booked before the sensor goes quiet.
Coverage in difficult buildings
Cold rooms, freezer banks, basements and plant rooms are hard places for radio. Insulated panels and metal doors block short-range signals that work fine in an office. LoRaWAN's low-frequency (868 MHz in the UK) signal copes better with walls and floors, and a weak signal that still arrives is a reading in the record.
Where a building is especially difficult, we add a gateway closer to the problem area. Our Link+ gateways send data to the cloud over their own Ethernet or 4G, with automatic 4G failover on the Link+ One and Link+ Pro, and the outdoor Link+ Pro is sealed to IP67 for yards and external stores.
Why range matters for the record
A monitoring record is only as good as its gaps. A system that drops readings because a sensor is at the edge of its range leaves holes an inspector will ask about. LoRaWAN's range reduces those holes, and a second layer covers the rest: if a sensor cannot reach a gateway, it stores up to 100 days of readings and resends them when the link returns.
- 14:00Gateway offlineA router fault takes the site link down.
- 14:00 to 16:30Sensor keeps loggingReadings are stored on the sensor every 5 minutes.
- 14:20Platform warnsThe platform flags the gateway as offline so someone can check it.
- 16:30Link restoredStored readings are resent automatically.
- 16:31Record completeThe trace shows every reading, with no gap.
How a Node+ fills a gap after an outage. Times are illustrative.
Where LoRaWAN is not the answer
LoRaWAN is built for fixed sites. For vehicles and assets on the move we use cellular trackers with Bluetooth sensors in the load space, because a lorry leaves gateway range within minutes of setting off. Both feed the same platform, so a pallet can be followed from the cold store to the vehicle. Our hardware guide covers which to use where.
To see how the whole chain fits together, from sensor to alarm, read how temperature monitoring systems work.
Questions people ask
How far can a LoRaWAN sensor reach?
Our Node+ sensors typically reach around 1 km inside buildings and up to 20 km in clear line of sight with an elevated antenna. Walls, racking and cold-room panels reduce that, so we survey each site before installing.
How long do the batteries last?
Up to 4 years at 5-minute logging and 8 years or more at 10 to 15 minutes, on two replaceable AA lithium cells. The platform shows each sensor's battery level, so changes can be planned.
Does LoRaWAN need our IT network?
No. The gateway sends readings to the cloud over its own Ethernet or 4G connection, so it does not need access to your clinical or office network. Ethernet models fail over to 4G automatically.
What is Sematics?
Sematics is the cloud monitoring platform the sensors report to. It stores readings, raises alarms and keeps the audit trail. JTF designs, installs, calibrates and supports it in the UK.
