What is LoRa ?
A Low-Power Wide-Area Network (LPWAN) or Low-Power Wide-Area (LPWA) network or Long range (LoRa) or Low-Power Network (LPN) is a type of wireless telecommunication wide area network designed to allow long range communications at a low bit rate among things (connected objects), such as sensors operated on a battery. The low power, low bit rate and intended use distinguish this type of network from a wireless WAN that is designed to connect users or businesses, and carry more data, using more power. The LPWAN datarate ranges from 0.3 kb/s to 50 kb/s per channel.
A LPWAN may be used to create a private wireless sensor network, but may also be a service or infrastructure offered by a third party, allowing the owners of sensors to deploy them in the field without investing in gateway technology.
LoRaWAN is a media access control layer protocol for managing communication between LPWAN gateways and end-node devices, maintained by the LoRa Alliance. Version 1.0 of the LoRaWAN specification was released in June 2015.
LoRa is a proprietary, chirp spread spectrum (CSS) radio modulation technology for LPWAN used by LoRaWAN, Haystack Technologies, and Symphony Link.
LoRa is a patented (EP2763321 from 2013 and US7791415 from 2008) technology developed by Cycleo (Grenoble, France) and acquired by Semtech in 2012. LoRa uses license-free sub-gigahertz radio frequency bands like 169 MHz, 433 MHz, 868 MHz (Europe) and 915 MHz (North America).
On top of this physical layer, there are two main competing protocols:
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 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.
UNB, Ultra Narrow Band, modulation technology used for LPWAN by various companies including:
- Sigfox, UNB-based technology and French company Telensa
- NB-IoT, another narrow band standard initiated and completed by 3gpp with their release 13 of the series of IoT standardizations
- Nwave, proprietary technology developed in cooperation with MIT. Its first release without error correcting codes also forms the basis of the Weightless-N open protocol
- Weightless, a set of communication standards from the Weightless SIG