Long Range LoRa and LoRaWAN - IoTThinks/EasyLoraGateway GitHub Wiki

1. What is LoRa?

LoRa is a patented wireless data communication technology developed by Cycleo of Grenoble, France, and acquired by Semtech in 2012.

  • LoRa uses license-free sub-gigahertz radio frequency bands like 169 MHz, 433 MHz (Asia), 868 MHz (Europe) and 915 MHz (North America).
  • LoRa enables very-long-range transmissions (more than 10 km in rural areas) with low power consumption.
  • The technology is presented in two parts โ€” LoRa, the physical layer and LoRaWAN, the upper layers.

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2. Why LoRa?

  • Long range: LoRa signal can travel multiple miles from 1 - 10 km or more.
  • Low power usage: The devices are inexpensive and can run for years without needing a battery change.
  • Suitable to IoT devices: This creates the ability to monitor devices that are difficult to access or out of range for wifi or cell service.

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3. Why NOT LoRa?

The caveat to this wonderful technology is the limited amount of bandwidth it offers.

  • Low bandwidth: In order to have such a long range and extended battery life, the frequency of a LoRa transmission must be very low.
  • More bandwidth vs. range: The more data you want to transfer at a time, the less distance and more battery you use. While it may seem pointless if you canโ€™t use it to stream Netflix, there are plenty of cases where range and reliability trump bandwidth.

4. Main terminologies

Four main configuration terminologies in LoRA.

  • Frequency: Commonly 433 MHz (Asia), 868 MHz (Europe) and 915 MHz (North America).
  • Preamble Length: A LoRa frame begins with a preamble. After the preamble, there is an optional header. E.g: 8 bits.
  • Spreading Factor: Number of bits encoded per symbol. The higher the spreading, the faster bandwidth and the shorter range. Eg: 7, 9, 12...
  • Signal bandwidth: The width of spectrum occupied by the chirp (the signal). E.g: 125Kbps
  • Coding Rate: This is a measure for the amount of forward error correction. E.g: 4/5

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5. LoRaWAN

LoRaWAN is a protocol specification built on top of the LoRa technology developed by the LoRa Alliance.

  • It uses unlicensed radio spectrum in the Industrial, Scientific and Medical (ISM) bands to enable low power, wide area communication between remote sensors and gateways connected to the network.
  • This standards-based approach to building a LPWAN allows for quick set up of public or private IoT networks anywhere using hardware and software that is bi-directionally secure, interoperable and mobile, provides accurate localization, and works the way you expect.
  • The specification is available for free to download from the LoRa Alliance website today.

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