LoRaWAN is a low-power long-range radio frequency protocol that allows devices to connect to the internet across vast distances. By bringing up dozens of new use cases, thanks to its long battery life (up to 5 years) and low sensor network maintenance costs, LoRaWAN has effectively solved a major problem in the Internet of Things ecosystem.
In this article, we'll look at the LoRaWAN architecture, important aspects of the core technology, and new emergent use cases.
The beauty of LoRaWAN is that it is based on an open standard. It operates in the ISM (Industrial, Scientific, and Medical) radio band, which is unlicensed. Using the unlicensed spectrum makes it simple for anybody to set up and manage their own network. In various places throughout the world, numerous telecom carriers have begun to adopt LoRaWAN as a technology and are providing connectivity along with service. Many companies, including KPN, Orange, SK Telecom, Comcast, and others, are deploying large-scale installations in their respective areas. This adds to the appeal of LoRaWAN as a technology, since it is interoperable with networks established by a variety of operators, from local to global.
LoRaWAN standard is governed by LoRa Alliance®.
LoRa is a wireless technology similar to WiFi, Bluetooth, LTE, and Zigbee, which are all commonly used. One technology cannot address all problems, and in many circumstances, trade-offs must be accepted. LoRa meets the demand for low-cost, battery-powered data transmission across large distances. LoRa, on the other hand, is not suitable for delivering data with high bandwidth.
LoRaWAN is a MAC protocol for a network of LoRa nodes with high capacity, long range, and low power consumption. It takes advantage of the above-mentioned LoRa characteristics to improve battery life and service quality for LoRa nodes. The protocol is entirely bidirectional, ensuring that messages are delivered reliably. It defines end-to-end encryption for security and data privacy, as well as end-node registration over the air and multicast functionality. The standard guarantees that different LoRaWAN networks throughout the world may communicate with one another.
End Nodes are physical hardware devices with sensing capabilities, computational power, and a radio module to transform data into a radio signal. These end devices may both send and receive data from a gateway.
When an end device sends a message to the gateway, it is referred to as ‘Uplink’ and when it receives a message back from the gateway it is called a ‘Downlink’. Based on this data, devices are classified into following categories:
With Class A being devices that take up the least energy, but can only send an uplink message after they receive a downlink message. These devices are suitable for sending data on a time-based interval (e.g. every 15 minutes) or for devices that send data event-driven (above a certain temperature level, etc.).
End nodes using Class B allow for more downlink message slots than for Class A. This reduces the latency for the messages but at the same time makes it less energy efficient.
Lastly, Class C have continuous receive windows that are only closed when the device is sending an uplink message. Due to this, it is the least energy efficient and in most of the cases needs a constant power source to operate.
Gateways are also known as modems or access points. A gateway is also a piece of hardware that collects all LoRaWAN communications from the End Nodes. These messages are then transformed to an array of bits that may be sent over standard IP networks.
Given low processing capacity, gateways are transparent; all complexity and intelligence is handled by the Network Server. Gateways are divided into two categories based on their use and purpose:
Outdoor Use Gateway, such as Kerlink IoT Station, LoRiX One
Indoor Use Gateway, such as Multitech Conduit, The Things Indoor Gateway
All the messages from the gateways are forwarded to the Network Server. This is where the more complicated processes of data handling take place. It is mainly responsible for:
Routing / Forwarding messages to the right application
Selecting the best gateway for downlink messages.
Removing duplicate messages if received by multiple gateways
Decrypting messages sent from end nodes & encrypting messages that are sent back to the nodes
Gateways typically connect to the network server on an encrypted Internet Protocol (IP) link. The network usually contains a gateway commissioning and supervision interface, allowing the network provider to manage gateways, handle breakdown situations, monitor alarms, etc...
An example of a LoRaWAN Network Server is The Things Stack by The Things Industries. It supports all LoRaWAN classes, all LoRaWAN versions (including v1.0.4 and v1.1) and all regional parameters specifications and has interoperability with other LoRaWAN networks (supports passive roaming, support for handover roaming in the future).
Scalability with LoRaWAN
LoRaWAN is intended for large-scale IoT deployments involving thousands of devices and a small number of gateways. These gateways can simultaneously listen to many channels and handle multiple messages.
Another important feature of LoRaWAN is the data transmission speed. Different data rates can be employed for data transmission; various data rates are referred to as Spreading Factors (or SF). Longer and more dependable range is possible with slower gearboxes.
To give you an example of how LoRaWAN works: imagine that you are trying to have a conversation with another person. When you are standing close, you are able to speak fast and the other person will perfectly understand you. But when you are standing far away, you need to speak much slower to get your message across.
LoRaWAN Use Cases
LoRaWAN is perfect for building different types of use cases on the same technology. With its unique characteristics, LoRaWAN is best applied in scenarios where:
Access to power (electricity) is limited or a constraint
Higher number of end devices than the one that cellular connection can handle
End devices do not need to broadcast messages continuously
This makes LoRaWAN attractive in agriculture, smart facilities, smart cities, cold chain and logistics verticals. Businesses are starting to understand the benefits and technology providers are managing to decrease the total cost of ownership of the deployments.
To learn more about LoRaWan, check out "The Things Conference 2022". This conference is the world’s largest LoRaWAN® event and enables you to join the top IoT professionals, industry players, buyers and builders. Learn more about the conference here.