LoRa

LoRa

File:LoRa Module with antenna and SPI wires attached.jpg A LoRa module
Developed by	Semtech
Connector type	SPI/I2C
Compatible hardware	SX1278
Physical range	10km+

LoRa (Long Range) is a low-power wide-area network (LPWAN) protocol developed by Semtech. It is based on spread spectrum modulation techniques derived from chirp spread spectrum (CSS) technology. It was developed by Cycleo of Grenoble, France and acquired by Semtech, the founding member of the LoRa Alliance.

Features

LoRa uses license-free sub-gigahertz radio frequency bands like 433 MHz, 868 MHz (Europe), 915 MHz (Australia and North America) and 923 MHz (Asia). LoRa enables long-range transmissions (more than 10 km in rural areas) with low power consumption. The technology covers the physical layer, while other technologies and protocols such as LoRaWAN (Long Range Wide Area Network) cover the upper layers. It can achieve data rate from 27 Kbps to 0.3 Kbps depending upon the spreading factor.

In January 2018, new LoRa chipsets were announced, with reduced power consumption, increased transmission power, and reduced size compared to older generation.

LoRa devices have geolocation capabilities used for trilaterating positions of devices via timestamps from gateways.

LoRa and LoRaWAN permit long-range connectivity for Internet of things (IoT) devices in different types of industries.

Range extenders for LoRaWAN are called LoRaX.

LoRa PHY

LoRa uses a proprietary spread spectrum modulation that is similar to and a derivative of chirp spread spectrum (CSS) modulation. The spread spectrum LoRa modulation is performed by representing each bit of payload information by multiple chirps of information. The rate at which the spread information is sent is referred to as the symbol rate, the ratio between the nominal symbol rate and chirp rate is the spreading factor (SF) and represents the number of symbols sent per bit of information. LoRa can trade off data rate for sensitivity with a fixed channel bandwidth by selecting the amount of spread used (a selectable radio parameter from 7 to 12). Lower SF means more chirps are sent per second; hence, you can encode more data per second. Higher SF implies fewer chirps per second; hence, there are fewer data to encode per second. Compared to lower SF, sending the same amount of data with higher SF needs more transmission time, known as airtime. More airtime means that the modem is up and running longer and consuming more energy. The benefit of high SF is that more extended airtime gives the receiver more opportunities to sample the signal power which results in better sensitivity.

In addition, LoRa uses forward error correction coding to improve resilience against interference. LoRa's high range is characterized by high wireless link budgets of around 155 dB to 170 dB.

LoRaWAN

Since LoRa defines the lower physical layer, the upper networking layers were lacking. LoRaWAN is one of several protocols that were developed to define the upper layers of the network. LoRaWAN is a cloud-based medium access control (MAC) layer protocol but acts mainly as a network layer protocol for managing communication between LPWAN gateways and end-node devices as a routing protocol, maintained by the LoRa Alliance.

LoRaWAN defines the communication protocol and system architecture for the network, while the LoRa physical layer enables the long-range communication link. LoRaWAN is also responsible for managing the communication frequencies, data rate, and power for all devices. Devices in the network are asynchronous and transmit when they have data available to send. Data transmitted by an end-node device is received by multiple gateways, which forward the data packets to a centralized network server. The network server filters duplicate packets, performs security checks, and manages the network. Data is then forwarded to application servers. The technology shows high reliability for the moderate load, however, it has some performance issues related to sending acknowledgements.

Version history

• January 2015: 1.0
• February 2016: 1.0.1
• July 2016: 1.0.2
• October 2017: 1.1, adds Class B
• July 2018: 1.0.3

LoRa Alliance

The LoRa Alliance is a 501(c)(6) association created in 2015 to support LoRaWAN (long range wide-area network) protocol as well as ensure interoperability of all LoRaWAN products and technologies. This open, nonprofit association has over 500 members. Some members of the LoRa Alliance are IBM, Everynet, Actility, MicroChip, Orange, Cisco, KPN, Swisscom, Semtech, A2A Smart City SPA, Bouygues Telecom, Singtel, Proximus and Cavagna Group. In 2018, the LoRa Alliance had over 100 LoRaWAN network operators in over 100 countries. The Alliance is administered by the VTM Group in Beaverton, Oregon. Geoff Mulligan was its chairman until 2018, when Donna Moore became the CEO and chairwoman.

Deployments of LoRa technology

• Reindeer tracking in Finland
• Glasgow IoT network
• IoT networks in Argentina, Brazil and Estonia
• Smart fire alarms and fire detection
• Smart Parking
• Black rhino poaching protection in Tanzania and endangered sea turtle monitoring in Peru
• Natural disaster prediction
• Cotton farming in Australia
• Utility metering in India
• Autonomous irrigation and soil health monitoring
• Smart water monitoring and water monitoring for commercial farms
• City-wide network in Calgary, Alberta, Canada
• IoT Network in Alba Iulia, Romania

• IoT Network in Gold Coast, Australia as part of required upgrades for the 2018 Commonwealth Games

See also

• DASH7 - a networking stack for LoRa
• IEEE 802.11ah – non-proprietary low-power long-range standard
• CC430 - an MCU & sub-1 Ghz RF transciever SoC
• NB-IoT
• LTE Cat M1
• Helium Systems - a proprietary protocol system based on similar technology
• MIoTy - Sub-GHz LPWAN technology for sensor networks.

Further reading

• Lee, Chang-Jae, Ki-Seon Ryu, and Beum-Joon Kim. "Periodic ranging in a wireless access system for mobile station in sleep mode." U.S. Patent No. 7,194,288. 20 March 2007.
• Quigley, Thomas J., and Ted Rabenko. "Latency reduction in a communications system." U.S. Patent No. 7,930,000. 19 April 2011.
• Bankov, D.; Khorov, E.; Lyakhov, A. "On the Limits of LoRaWAN Channel Access". 2016 International Conference on Engineering and Telecommunication (EnT): 10–14.
• Seneviratne, Pradeeka. "Beginning LoRa Radio Networks with Arduino - Build Long Range, Low Power Wireless IoT Networks." Apress, 2019, eBook ISBN 978-1-4842-4357-2, Softcover ISBN 978-1-4842-4356-5, Ed: 1

External links

• LoRa Alliance
• LoRaWAN as wide-area, low-power, private IoT network
• RAKwireless pioneer in LPWA connectivity solutions for IoT infrastructures and Edge Devices.de:Long Range Wide Area Network

• Version 1.0 of the LoRaWAN specification released.
• https://www.nnnco.com.au/news/article/city-of-gold-coast-to-build-australias-biggest-lorawan-network-with-iot-operator-nnnco/