What Is LoRaWAN? How It Works and Why It Suits Smart Buildings

LoRaWAN (Long Range Wide Area Network) is an open, low-power wireless protocol that lets battery sensors send small amounts of data over kilometres.

LoRaWAN has become the default way to add wireless sensors to commercial buildings. A sensor the size of a matchbox can report temperature, CO2 or occupancy for years on one battery, through walls and floors, without a cable. This guide explains what LoRaWAN is, how the network is built, what the jargon means, the UK radio rules, how secure it is, and where it fits in a building management system.

What does LoRaWAN stand for?

LoRaWAN stands for Long Range Wide Area Network. It is a LPWAN (low-power wide-area network) protocol published and maintained by the LoRa Alliance, an open, non-profit association of hundreds of companies. Because it is an open standard, sensors, gateways and network servers from different manufacturers work together, and you are not tied to one supplier.

LoRa vs LoRaWAN: what is the difference?

The two names are often used interchangeably, but they are different layers:

LoRa uses chirp spread spectrum modulation, which spreads each bit across a wide band of frequencies. That makes signals very resistant to interference and detectable even below the noise floor, which is where the long range comes from. LoRaWAN builds the network on top of it. You can use LoRa without LoRaWAN for simple point-to-point links, but for buildings you want LoRaWAN's security, interoperability and network management.

How a LoRaWAN network works

LoRaWAN uses a star-of-stars topology with four parts.

1. End devices (sensors and actuators)

Battery or mains-powered devices that measure or control something: temperature and humidity sensors, CO2 monitors, people counters, leak detectors, current transformers, radiator valves. They transmit short messages, called uplinks, by radio. Devices do not connect to a particular gateway; every gateway in range hears every message.

2. Gateways

A gateway listens on several radio channels at once and forwards every packet it hears, unchanged, to the network server over Ethernet, Wi-Fi or 4G. Gateways do not decode or own devices; they are simply radio-to-IP bridges. Indoor gateways such as the Milesight UG65 and outdoor gateways such as the UG67 are common in buildings; see our LoRaWAN gateways. An IONA-I Niagara 4 controller can also act as the gateway (see IONA option cards).

3. Network server

The network server is the brain of the network. It:

• authenticates devices and checks message integrity
• removes duplicates when several gateways hear the same message
• chooses the best gateway for any message back to the device (a downlink)
• manages data rates through adaptive data rate (ADR)
• handles device joins with a join server

The network server can run in the cloud, on a gateway (many Milesight gateways include one), or inside a controller such as IONA.

4. Application server

The application receives decrypted data from the network server, decodes the payload (sensor messages are compact binary, not readable values) and passes the results to where they are used: a BMS, a dashboard, a database. In a Niagara system the application is the station itself, through a driver or MQTT integration, so each value becomes an ordinary point.

LoRaWAN device classes

Most building sensors are Class A. Devices that you need to command quickly, such as a valve controller or relay, are usually Class C and mains or 24 V powered.

How devices join: OTAA and ABP

Before a device can send data it must join the network.

• OTAA (Over-The-Air Activation) is the recommended method. The device holds a DevEUI, JoinEUI (AppEUI) and a secret AppKey. It sends a join request, the network server verifies it, and fresh session keys are generated. Keys are refreshed whenever the device rejoins.
• ABP (Activation By Personalisation) hard-codes the session keys into the device. It is simpler but less secure and less flexible, and is best avoided for new deployments.

LoRaWAN in the UK: frequencies and rules

In the UK and Europe, LoRaWAN uses the EU868 band, 863–870 MHz, which is licence-exempt. Anyone can deploy a network without a radio licence, provided devices follow the rules for short-range devices, including duty cycle limits: on the main LoRaWAN channels a device may transmit for no more than 1% of the time (36 seconds per hour). In practice this is ample for sensors that report every few minutes.

Other regions use different bands, such as US915 in North America and AS923 in parts of Asia, so always buy EU868 devices and gateways for UK sites. "868 MHz antenna" in a product name refers to this band.

Data rates and spreading factors

LoRa trades speed for range using a spreading factor (SF) from SF7 to SF12:

Devices close to a gateway use a low SF: fast, short time on air, low battery use. Distant devices use a high SF to be heard. ADR lets the network server move each device to the fastest rate that still works reliably. LoRaWAN is therefore designed for small, infrequent messages: a reading every few minutes, not a video stream. Maximum payload ranges from 51 bytes at SF12 to over 200 bytes at the faster rates. See LoRaWAN range and gateway planning.

How secure is LoRaWAN?

LoRaWAN encrypts data by default with AES-128 at two levels:

• a network session key protects message integrity between device and network server, so messages cannot be forged or altered
• an application session key encrypts the payload end to end between device and application, so even the network server cannot read the content

Frame counters prevent replay attacks. The main risks lie in how keys are handled: keep AppKeys secret, use OTAA, and secure the network server and application like any other IT system.

LoRaWAN vs other wireless technologies

For building sensors, LoRaWAN's combination of range, penetration through walls and floors, battery life and independence from corporate IT is hard to beat. Wi-Fi drains batteries and needs IT approval; mesh networks need many mains-powered nodes; cellular IoT adds per-device subscriptions.

LoRaWAN in smart buildings

Typical building applications:

• Indoor air quality: temperature, humidity, CO2, TVOC and particulates (LoRaWAN IAQ and CO2 sensors)
• Occupancy and people counting: desks, meeting rooms, floors and entrances (people counting and occupancy sensors)
• Energy monitoring: smart current transformers, pulse counters and meter readers
• Water: leak detection, tank levels, legionella temperature monitoring
• Heating control: LoRaWAN smart thermostats and radiator actuators
• Facilities: smart washrooms, bin levels, door contacts, panic buttons

Because the sensors are wireless, they are ideal for retrofits, listed and heritage buildings, occupied buildings, temporary layouts, and places where cabling would be disruptive or expensive.

Bringing LoRaWAN data into a BMS

Wireless sensors only deliver value when their data reaches control and reporting. With Niagara 4 there are three common routes:

1. IONA-I with integrated LoRaWAN: the controller is the gateway and network server, and sensor values arrive directly as points.
2. Separate gateway with built-in network server (for example a Milesight UG65), integrated into Niagara through the Tyrrell Products LoRaWAN for Milesight driver or MQTT.
3. Cloud network server (for example The Things Stack), integrated through MQTT.

Once in Niagara, LoRaWAN values can drive real control: CO2 adjusting ventilation, occupancy setting back heating, a leak sensor closing a valve. Watch the LoRaWAN for Milesight video in our Niagara 4 driver guides.

Private vs public LoRaWAN networks

You can run LoRaWAN in two ways:

• Private network: you own the gateways and run the network server yourself, on a gateway, an IONA controller, or your own server. No subscription, full control of data, and coverage exactly where you need it. This is the usual choice for buildings and campuses.
• Public or community network: an operator or community provides gateways and a network server, and you connect your devices to it. Useful for widely scattered devices across a city, but coverage inside a specific building is not guaranteed and you depend on a third party.

For BMS use, a private network is almost always the right answer: building data stays inside your control system and coverage can be engineered for the building.

Getting started: a LoRaWAN pilot

The best way to prove LoRaWAN in your estate is a small pilot:

1. Pick one building and one clear goal, such as CO2 in meeting rooms or temperatures in a hard-to-heat area.
2. Install one gateway (or an IONA-I controller) in a good position.
3. Deploy 10 to 30 sensors, including a few in the most difficult locations.
4. Integrate the data into the BMS and set up alarms and a simple dashboard.
5. Run it for a month, check link quality and battery forecasts, and measure what changed.

A pilot answers the coverage, integration and value questions with real data before you commit to a full roll-out.

Browse LoRaWAN products

Tyrrell Products stocks LoRaWAN sensors and IoT devices, LoRaWAN gateways and LoRaWAN accessories from Milesight, Elsys and others, with UK stock and support.

Frequently asked questions

What is LoRaWAN used for?

LoRaWAN connects battery-powered sensors that send small amounts of data over long distances: in buildings, typically air quality, temperature, occupancy, energy, water leak and facilities sensors.

Is LoRaWAN free to use?

The radio spectrum (EU868 in the UK) is licence-exempt, so there is no airtime charge. You pay for devices, gateways and any network server or cloud service you choose; running your own gateway and network server has no subscription.

Is LoRaWAN better than Wi-Fi?

For battery sensors, usually yes: far longer range and battery life and no load on corporate Wi-Fi. Wi-Fi is better for devices that need high bandwidth.

What frequency does LoRaWAN use in the UK?

The EU868 band, 863–870 MHz, licence-exempt, with duty cycle limits of typically 1% per device on the main channels.

How far can LoRaWAN reach?

Several kilometres outdoors in open terrain and much further with line of sight; indoors, typically several floors of a building per gateway, depending on construction.

What is a LoRaWAN gateway?

A LoRaWAN gateway receives radio messages from every sensor in range and forwards them over IP to a network server. It does not own devices or decode data; it is a radio-to-network bridge.

Is LoRaWAN obsolete?

No. LoRaWAN is an actively developed open standard with a large and growing device ecosystem, and is widely used for smart buildings, utilities and smart cities.

Related guides

• LoRaWAN range and gateway planning
• LoRaWAN indoor air quality and CO2 sensors
• People counting and occupancy sensors
• IONA option cards: LoRaWAN and 4G
• Smart building management systems