Tech Trends: LoRa Technology Stretches the IoT

Sept. 13, 2019
Long range tech will enable the deployment of IoT security sensors over extended distances

Here’s a question: What do cattle in Australia and traffic lights in India have in common?

Stumped? Well, each was the topic of a separate article in IEEE’s Spectrum magazine earlier this year, and both groups are using an interesting new technology that will significantly contribute to the continued growth of IoT – it is called LoRa, short for Long Range as in long-range low-power wireless communications.

LoRa enables ear tags manufactured by Dutch company Sodaq to track the whereabouts of a rancher’s cows in Australia; while in Mumbai, India, the technology not only enables the control of traffic lights but facilitates smart meters and a host of other applications.

Think about the IoT devices you may have encountered and how they were connected to the network. If not connected via direct cable, they likely used Bluetooth or Wi-Fi – neither of which have more than a very limited range to their destination or access point.

Thus, a wireless technology that can work up to several kilometers at a low enough energy level not to drain a device’s battery too quickly can be an exciting proposition. That is can enable the IoT universe to be expanded to include reindeer in Finland, bike sharing services, rhino protection in Africa, ubiquitous sensors to warn of impending disaster conditions, utility and water metering, and much more.

How it Works

According to Wikipedia, “LoRa (Long Range) is a spread spectrum modulation technique derived from chirp spread spectrum (CSS) technology and is the first low-cost implementation of chirp spread spectrum for commercial usage. It was developed by Cycleo of Grenoble, France, and acquired by Semtech in 2012, a founding member of the LoRa Alliance.”

Chirp spread spectrum modulation maintains the same low power characteristics as Frequency Shift Keying (FSK) modulation but significantly increases communication range. It allows better performance with respect to channel noise, multipath fading and Doppler effects.

Low Power WANs (LPWAN) were originated to tie low-power devices into a network fabric, encompassing both cellular and non-cellular techniques from the device. LPWANs enable solutions providers to design IoT systems for use cases that require devices to send small amounts of data periodically over often-remote networks that span many miles and use battery-powered devices that need to last many years. As I wrote in my July column, 5G will impact IoT growth in significant ways; additionally, LTE-Cat M1 and NB-IoT are cellular LPWAN alternatives.

A non-cellular (from the device) alternative is LoRaWAN®, a specific media access control (MAC) LPWAN protocol for wide area networks which works in conjunction with LoRa (and FSK) modulation in an unlicensed portion of the spectrum. In the United States, that frequency range is 902 to 928 MHz with dedicated 125 KHz or 500 KHz uplink and 500 KHz downlink channels. The LoRaWAN specification is developed and maintained by the LoRa Alliance and provides seamless interoperability between manufacturers, as demonstrated via the Alliance’s device certification program (learn more at https://lora-alliance.org/about-lorawan.)

An IoT end-device serves a specific function or application and communicates its information through an embedded communications circuit. Remote end-devices are typically battery powered (batteries themselves being the subject of cutting edge research). Communication falls into three classes:

  • Class A, which all LoRaWAN devices must support, provides for bi-directional communication between a device and a gateway with the ability to transmit anytime and receive with specified windows of time after the uplink transmission. Class A devices have the lowest power consumption, highest downlink latency, and may include fire detection and early earthquake detection.
  • Class B (beaconing class) extends the receive function to scheduled windows using time-synchronized beacons from the gateway for applications such as smart metering and temperature monitoring and has relatively low latency.
  • Class C (continuously listening) has open receive windows except for when the device is transmitting and may be employed in fleet management and real time traffic management. It has the lowest latency but highest power consumption.

Gateways serve as concentrators and connect to the network server via standard IP connections, acting as a transparent bridge to convert RF packets to IP packets. End-devices (network nodes) are not associated with any specific gateway and may in fact communicate to multiple gateways. In turn, these forward the received packets from the end devices to a cloud-based network server via backhaul (either cellular, Ethernet, satellite, Wi-Fi).

The network server manages the network and filters redundant received packets from each device, performs security checks, and schedules acknowledgments through the gateway determined to be optimal. If a device is mobile, there is no handover needed from gateway to gateway. From the network server, information is passed to an application or customer server which operates on the data.

LoRaWAN uses two layers of security. Network security ensures authenticity of the node in the network. An application layer of security ensures privacy of the end user’s application data. AES encryption is used with the key exchange utilizing an IEEE EUI64 identifier, generated from the device’s MAC address.

Implications for Security

The IoT is inevitable and growing quickly, so you would do well to understand the technologies that will drive it. Network-connected security devices may be considered a part of the IoT space.

The technology I have described here contributes the ability to expand and deploy security sensors – perimeter, environmental, fire, gas detection, etc. – over extended distances without external power and beyond Wi-Fi range. An example would be DoorKing’s new 900MHz Wireless Expansion Kits, which use LoRa technology to add access points in hard-to-wire places.

These sensor networks will be an important component of future security deployments. Asset and personnel tracking applications also achieve enhanced flexibility and capability – as long as they can hit a gateway (or cell tower for cellular LPWANs), they can remain connected and useful.

Ray Coulombe is Founder and Managing Director of SecuritySpecifiers and the CONSULT Technical Security Symposium. Reach him at [email protected], through LinkedIn at www.linkedin.com/in/raycoulombe or follow him on Twitter, @RayCoulombe.