LoRa or Long Range is a digital wireless data communication protocol developed by Cycleo of Grenoble, France. Semtech, a leading supplier of supplier of analog and mixed-signal integrated circuits, and the parent company of Cycleo, owns the IP for LoRa transmission technique.
LoRa is a long-range wireless communication protocol that transmits over sub-gigahertz radio frequency bands such as 169 MHz, 433 MHz, 868 MHz and 915 MHz. Very long range transmission of over 10 km in rural areas are enabled by LoRa even at a low power consumption.
What does the technology comprise of?
The physical layer is LoRa upon which a communication protocol is built. The communication layer can be Long Range Wide Area Network (LoRaWAN) or Symphony Link.
LoRaWAN is a networking protocol designed to wirelessly connect battery-operated devices to the internet across global national or regional networks. It meets IoT requirements such as bi-directional communication, mobility, end-to-end security and localization services. LoRaWAN is defined by the LoRa Alliance, a non-profit consortium of over 500 member companies whose objective is to enable the large scale deployment of Low Power Wide Area Networks (LPWAN) by developing and promoting the LoRaWAN open standard. Technology suppliers forming the alliance include Cisco, IBM, Actility and IMST to name some, while telecoms members include Bouygues Telecom, SingRel, Swisscom, KPN, FastNet and Proximus.
Symphony Link is an open source wireless system built by Link Labs. It is used by enterprise and industrial customers who appreciate the range of LoRa but require high reliability and advanced features in their LPWA system.
Features of LoRa
LoRa is a spread spectrum modulation technique, which indicates a method by which an electrical, electromagnetic or acoustic signal generated with a certain bandwidth is deliberately spread in frequency domain, resulting in a signal with a wider bandwidth. It is derived from chirp spread spectrum (CSS) technology, a spread spectrum technique that uses wideband linear frequency modulated chirp pulses to encode information.
LoRa allows the amount of spread used to be selected, which helps determines the data rate and influences the sensitivity of a radio. To address interference, the communication technology uses Forward Error Correction Coding (FEC). This is a technique employed to control errors in data transmission over noisy or unreliable communication channels. The sender encodes the message in a redundant way by using error-correcting code (ECC).
Within the sub-GHz spectrum, LoRa chips can transmit at a variety of frequencies and data rates. This capability helps the gateway in adapting to changing conditions and optimizing data exchange with each device.
Network topology of LoRa and LoRaWAN
LoRaWAN network architecture is deployed as a star-of-stars topology. Here, the gateways relay messages between end devices and a central network server. The gateways are connected to the network server via standard IP connections and serve as a transparent bridge converting RF packets to IP packets and vice versa.
End Nodes and Gateways
The end nodes of the architecture are LoRa embedded sensors. The nodes have sensors that detect changing temperature, humidity, GPS and other parameters; a LoRa transponder to emit signals over LoRa patented radio transmission methods; and may optionally feature a micro-controller with on-board Memory.
The LoRaWAN end nodes usually employ Low Power and Class A or Class B batteries. Battery-driven LoRa embedded sensors can last anywhere from two to five years. The sensors can transmit signals over distances of 1km to 10km.
LoRa sensors transit data to LoRa gateways, which connect to the internet via the standard IP protocol and convey the data from LoRa embedded sensors to the internet, which can be a server, network or cloud.
Perpetually connected to a power source, the Gateway devices connect to the network server via standard IP connections, and as mentioned previously, do the job of converting RF packets to IP packets and vice-versa.
Network and Application Servers
Network servers are either LoRIOT, which is a network operator of LoRaWAN networks, or The Things Network (TTN), an open and a decentralized internet of things network that allows for things to connect to the internet using little power and little data. The network servers connect to the gateways and de-dup data packets, and then route them to the particular application. They can be used for sensor-to-application/uplink or application-to-sensor/downlink communication.
The TTN server comprises a router, broker and handler, which process data packets from the LaRaWAN gateway and also consist of an AWS bridge connecting TTN to the AWS IoT platform.
The application can be built over IoT platforms such as AWS IoT using Dynamo, S3 or Lambda services.
Security of LoRaWAN
LoRaWAN uses two layers of security at the network and application levels. The network security layer safeguards the authenticity of the node in the network; the application layer prevents the network operator from gaining access to end users’ application data.
The LoRaWAN specification also has two layers of cryptography: A unique 128-bit Network Session Key shared between the end-device and network server, and a unique 128-bit Application Session Key (AppSKey) shared end-to-end at the application level.
Data transmitted over LoRaWAN is encrypted twice. The sensor data is encrypted by the node and once again by the LoRaWAN protocol prior to being sent to the LoRa Gateway. The Gateway transmits data over the normal IP network to the network server.
LoRa Gateways need to operate over open frequency in order for them to receive data from any sensor the immediate surrounding. For this reason, LoRa Gateways lack the ability to decrypt sensor data.
Advantages of LoRaWAN
- Ensure a wide coverage area at a low power consumption
- Run on unlicensed frequencies, removing the need for upfront licensing costs
- Simple architecture ensures easy deployment
- A single LoRa Gateway device can handle thousands of end devices or nodes
- The use of low power sensors translates to long battery life for devices
- Low bandwidth enables practical IoT deployments
- Cheaper connectivity costs
- An alliance with an Open approach in contrast to a proprietary one such as SigFox
Disadvantages of LoRaWAN
LoRaWAN technology is yet to be an ideal solution for private networks for the following reasons:
- Packet error rates exceeding 50% are common given that LoRaWAN is an asynchronous protocol with limited acknowledgements.
- Does not possess the ability of real-time power and data rate control
- Only one network can operate in an area without interference
- The use of pre-shared keys and identities poses security vulnerabilities
- To operate a public LoRaWAN network, the entity must be granted a NetID by the LoRa Alliance
Even though LoRaWAN has been deployed in more than 50 countries, it can be said to be in its infancy. It is expected that the number of countries that will adopt LoRaWAN will double in the next five years. Comcast has already established LoRaWAN in Philadelphia and planning to expand to San Francisco and Chicago. The company will employ LoRa unlicensed narrowband network for business solutions such as GPS-less tracking and waste management.
The growing deployment of LPWA technologies, including LoRa, portends a positive future. The North American LPWAN market is expected to account for more than 40% industry share by 2025 on the back of advanced IoT infrastructure and smartphone penetration. A 2019 Global Market Insights, Inc report predicts a rise in the LPWAN market to USD 65 billion by 2025. Also consider that LoRa is not competing against technologies such as Wi-Fi, Bluetooth and home automation wireless technology, all of which also have big growth prospects.
LoRa’s future is bright in today’s highly connected world where IoT is steadily posed to gain mainstream status. Prior to LoRa, the Internet of Things concept faced obstacles such as device and battery capabilities, network traffic and security. LoRa addresses this problem by allowing more devices to be served by the network without putting stress on the power source. With 128 AES encryption for the application service, network server and end device, LoRa is also a secure solution.
Applications of LoRaWAN
LoRaWAN has a number of applications across industries, and can also improve the civil infrastructure of cities. A current or future smart city has the opportunity to leverage the technology for such purposes as air quality and pollution monitoring, smart lighting, fire detection and management, and smart parking and vehicle management.
Reindeer tracking is an ingenious use of LoRaWAN. It was reported in 2018 that Finnish reindeer herders were testing a LoRaWAN-based solution on alpha female reindeer to track herds comprising thousands of animals and automatically detect when they might be in danger from vehicles or predators.
LoRaWAN is also suitable for numerous industrial applications, across shipping and transportation, item location and tracking, and radiation and leak detection. This year, Australian farmers will start using IoT connectivity to power irrigation. The 3 million hectare LoRaWAN network will provide data on soil moisture to aid better scheduling of irrigation. The network will enable this capability at a lower cost compared to traditional cellular connectivity.
In the healthcare industry, LoRa’s applications extend to wearable technology and health monitoring devices and management. Semtech Corporation in collaboration with IoT terminal devices developer Movtek has developed a LoRa-based wearable device that tracks users’ exact location using GPS technology. The gateway is integrated in users’ Smart Home. The technology is deployed in smart watches and bracelets worn by seniors and children who need to be monitored for safety.
As far as home applications are concerned, LoRa offers immense potential to deliver home automation for IoT-enabled smart appliances as well as enhance home security.