Semtech’s proprietary low power wide area network (LPWAN), LoRa (Long Range), is a fairly recent entrant to the IoT protocol wars. Now it has got its very own alliance, with a ready mix of kit vendors and telcos. The LoRa Alliance’s mission is to “standardize LPWANs being deployed around the world, to enable IoT, M2M, smart city and industrial applications.”
The founding members are, on the hardware side of things: Actility, Cisco, Eolane, IBM, Kerlink, IMST, MultiTech, Sagemcom, Semtech and Microchip. These companies are joined by telecom operators: Bouygues, KPN, SingTel, Proximus, Swisscom and FastNet (Telkom South Africa). It will operate as an independent and non-profit entity.
Together, the alliance says its members intend to collaborate on driving the adoption of LoRaWAN, by sharing knowledge and making sure the telcos can talk freely to each other – a key requirement if you plan on supporting global deployments or equipment that will travel beyond the reaches of your home telco provider, as is the case in industrial and logistics deployments.
“The LoRa technology is ideal to target battery operated sensors and low power applications, as a complement to M2M cellular connectivity,” said Richard Viel, COO at Bouygues Telecom. “The LoRa Alliance is an essential step to ensure interoperability, and therefore, mobility across Europe for our customers.”
IBM has also released its LoRaWAN in C (the programming language) under the Eclipse Public License, which should help developers get to grips with the protocol more quickly, and should only aid adoption. Thorsten Kramp, IBM’s Master Inventor, adds “to encourage the mass adoption of low cost, long range M2M connectivity, open ecosystems are critical. LoRaWAN in C provides a solid foundation for the development of a broad range of compliant devices.”
According to Semtech, LoRa has a greater range than cellular and uses a fraction of the power. Semtech designed the LoRa gateway chips, and partnered with IBM Research, Actility, and Microchip to develop the LoRaMAC protocol.
LoRa is a long-range star network architecture, which Semtech says has much higher network capacity than competing solutions and can enable battery lives measure in years. The gateways transfer messages from the network edge to a central cloud, which is also capable of multicasting messages or OTA updates. It operates in the 868MHz and 915MHz bands, which move its transmissions away from the sometimes heavily congested cellular and WiFi bands.
LoRa’s network servers use an adaptive data rate that will optimize network capacity and battery lifetimes, according to the company. This is because most network deployments today use a single data rate that runs into trouble when a network node needs more capacity but can’t get it. To solve the problem of an overloaded node, an operator must add additional nodes, or deploy a new technology.
Semtech’s alternative approach would allow the node to turn down data rates if it is overloaded, and also to boost data rates when it has spare capacity. Similarly, this means that range or data rate can be prioritized, depending on the circumstances, with bandwidth varying from 0.3 kbps to 50 kbps. As most IoT transmissions will be small in nature, Semtech is confident that thousands of devices can be run from one node.
While yet to be deployed in a smart city scheme or government project, Semtech’s LoRa chips have made their way into Cisco’s IR910 series of gateways, which have been used in smart city trials in San Francisco in August this year. In that trial, a single gateway had a 40-mile range, from San Francisco to San Jose, which Cisco points out is more than enough to manage a fully deployed smart city project.
Olivier Hersent, CEO of Actility, says that entire cities or countries can be covered with a few base stations, no longer requiring the upfront cost of a rollout or the maintenance of thousands of masts, as is the case with mesh networks.
The nodes or gateways are manufactured by Kerlink, IMST and MultiTech. A developer would choose a gateway from one of these firms, and then provision the gateway to a network controller – supplied by Actility or Future Electronics, who will distribute the cloud-based IBM network controller system.
The next step for the developer is to select a LoRaMAC compliant module for their devices. These modules are currently manufactured by IMST and Microchip, and the LoRaMAC protocol is embedded in the module. In theory, this allows the developer to just focus on their API, instead of having to configure the module itself. A fee is then charged for hosting the cloud-based IBM network controller.
LoRa claims to have ten times the range of competing protocols, with a 2-5km range in dense urban environments and up to 15km in suburban locales, with tens of thousands of devices per SX1301 gateway – which is substantially shorter than the 40 mile range claimed by Cisco. It also claims a 9.7mA receive mode, and a 100nA sleep mode – hence the long battery life.