Since last few years everyone has been talking about how Internet of Things will change our world. But the vision of connecting billions of devices has certain challenges. The current available wireless networks like Bluetooth, Bluetooth Low Energy, WiFi and ZigBee are not suitable for long range applications. Cellular networks too can’t be used for remote machine-to-machine communication because of high battery inefficiency. Overall, all these networks are very expensive as far as hardware and services are concerned.
Major IoT applications require only transmitting tiny bits of data to monitor remote devices. Cellular systems are not geared for battery efficiency or moving little bits of data inexpensively. So, a Low Power Wide Area Network (LPWAN) is required for such applications. LPWAN is suitable for sending small amounts of data over a long range, while maintaining a long battery life.
What Is LoRa?
LoRa™ (Long Range) is a modulation technique based on spread-spectrum techniques and a variation of Chirp Spread Spectrum (CSS), which provides significantly longer range than the competing technologies. The LoRa wireless technology was developed by Cycleo SAS, which was later acquired by Semtech.
What is LoRaWAN?
The LoRa modulation is the physical layer of LoRaWAN, which is a MAC protocol for a high capacity long range and Low Power Wide Area Networks (LPWAN). LoRa Alliance which is an open-nonprofit association of members is working to standardize LoRa Wide Area Network protocol (a.k.a. LoRaWAN) for LPWAN. LoRaWAN targets the basic needs of IoT such as secure bi-directional communication, mobility and localization services.
Image Source: Lora Alliance
Moreover, the LoRaWAN network server manages the data rate and RF output for each end-device individually by means of an adaptive data rate (ADR) scheme which extends the battery life of the remote end devices up to 10 years, and also increases the overall network capacity to a great extent.
How Does LoRaWAN Work?
LoRaWAN network architecture is typically laid out in a star-of-stars topology in which Gateways are a transparent bridge relaying messages between end-devices and a central network server in the backend. Gateways are connected to the network server via standard IP connections while end-devices use single-hop wireless communication to one or many gateways.
A single LoRaWAN Gateway covers more than 10 Km in range and are comparatively cheaper. With the benefit of LoRaWAN’s long range, The Things Network covered the city of Amsterdam with just 10 gateways at the cost of 1200 dollars.
Since LoRaWAN is being designed in such a way that it can be used to create a nation wide network and help building critical infrastructure of Internet of Things, security is a big concern. The LoRa Alliance has tried to make the LoRaWAN very secure by adding three different layers of security:
- Unique Network key to ensure security on network level
- Unique Application key to ensure end to end security on application level
- Device specific key
Although there are other choices for LPWAN like Sigfox, this LoRa based LPWAN looks more promising and is more popular. We recently shared how Tata Communications has chosen LoRa for its LPWAN for Internet of Things in India.