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LoRa

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Not to be confused with LORAN.
For the deep learning fine-tuning technique, see Fine-tuning (deep learning) § Low-rank_adaptation.
LoRa
SX1278, a LoRa module
Developed byCycleo, Semtech
Connector typeSPI/I2C
Compatible hardwareSX1261, SX1262, SX1268, SX1272, SX1276, SX1278
Physical range330 kilometres (210 mi) in perfect conditions.[1] Approximately 10 kilometres (6.2 mi) in practical conditions
Example of LoRa modulation. Base or center frequency is 432.995 MHz, SF=12 and bandwidth=7.8kHz. In the yellowgreen area time is downwards and at the top time=0 (current time). The radio transmitter is a RTL-SDR-dongle (2.5 Msps).

LoRa (from "long range") is a physical proprietary radio communication technique based on spread spectrum modulation.[2] LoRa can be thought of as the radio signal technology (similar to Wi-Fi or cellular).[3]

The technology is primarily used for applications where small amounts of data need to be transmitted infrequently from hard-to-reach locations.

Features

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LoRa uses license-free sub-gigahertz radio frequency bands EU433 (433.050-434.790 MHz) or EU868 (863–870/873 MHz) in Europe; AU915/AS923-1 (915–928 MHz) in South America; US915 (902–928 MHz) in North America; IN865 (865–867 MHz) in India; and AS923 (915–928 MHz) in Asia;[4] LoRa enables long-range transmissions with low power consumption.[5] The technology covers the physical layer, while other technologies and protocols such as LoRaWAN cover the upper layers. It can achieve data rates between 0.3 kbit/s and 27 kbit/s, depending upon the spreading factor.[6]

Description

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LoRa uses a proprietary spread spectrum modulation that is similar to and a derivative of chirp spread spectrum (CSS) modulation. Each symbol is represented by a cyclic shifted chirp over the bandwidth centered around the base frequency.

The spreading factor (SF) is a selectable radio parameter from 5 to 12[7] and represents the number of bits sent per symbol and in addition determines how much the information is spread over time.[8] There are different initial frequencies of the cyclic shifted chirp across the bandwidth around the center frequency.[9]

The symbol rate is determined by . LoRa can tradeoff data rate for sensitivity (assuming a fixed channel bandwidth ) by selecting the SF, i.e. the amount of spread used. A lower SF corresponds to a higher data rate but a worse sensitivity, a higher SF implies a better sensitivity but a lower data rate.[10] Compared to lower SF, sending the same amount of data with higher SF needs more transmission time, known as time-on-air. More time-on-air means that the modem is transmitting for a longer time and consuming more energy.

Typical LoRa modems support transmit powers up to +22 dBm.[7] However, the regulations of the respective country may additionally limit the allowed transmit power. Higher transmit power results in higher signal power at the receiver and hence a higher link budget, but at the cost of consuming more energy. There are measurement studies of LoRa performance with regard to energy consumption, communication distances, and medium access efficiency.[11] According to the LoRa Development Portal, the range provided by LoRa can be up to 3 miles (4.8 km) in urban areas, and up to 10 miles (16 km) or more in rural areas (line of sight).[12]

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.[13]

Range extenders for LoRa are called LoRaX.

Applications

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LoRa applications:

  • Meshtastic – an open source mesh network protocol that uses LoRa flood messaging
  • MeshCore - open source mesh network protocol that uses LoRa with more structured routing than Meshtastic
  • LoRaWAN - uses LoRa. a low-power, wide-area network (LPWAN) protocol that wirelessly connects battery-operated devices to the Internet
  • ExpressLRS – open source UAV remote control protocol that uses LoRa, widely used in FPV drones
  • Amazon Sidewalk – a mesh wireless network developed by Amazon. Uses LoRa for long range

See also

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  • DASH7 – a popular open alternative to LoRa
  • IEEE 802.11ah – non-proprietary low-power long-range standard
  • CC430 – an MCU & sub-1 GHz RF transceiver SoC
  • Narrowband IoT – narrowband Internet of things
  • LTE Cat M1 – Cellular device technology
  • MIoTy – sub-GHz LPWAN technology for sensor networks
  • SCHC – static context header compression
  • Short-range device – Class of radio transmitter

References

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  1. ^ "Range Tests | Meshtastic". meshtastic.org. Retrieved 2025-01-22.
  2. ^ "What is LoRa?". Semtech. Retrieved October 3, 2025.
  3. ^ Haxhibeqiri, J.; Van den Abeele, F.; Hoebeke, J.; Moerman, I. (2018). "A Survey of LoRaWAN for the Internet of Things". LoRaWAN for smart city applications. Springer. pp. 1–25.
  4. ^ "RP002-1.0.3 LoRaWAN Regional Parameters" (PDF). lora-alliance.org. Retrieved 9 June 2021.
  5. ^ Ramon Sanchez-Iborra; Jesus Sanchez-Gomez; Juan Ballesta-Viñas; Maria-Dolores Cano; Antonio F. Skarmeta (2018). "Performance Evaluation of LoRa Considering Scenario Conditions". Sensors. 18 (3): 772. Bibcode:2018Senso..18..772S. doi:10.3390/s18030772. PMC 5876541. PMID 29510524.
  6. ^ Adelantado, Ferran; Vilajosana, Xavier; Tuset-Peiro, Pere; Martinez, Borja; Melia-Segui, Joan; Watteyne, Thomas (2017). "Understanding the Limits of LoRaWAN". IEEE Communications Magazine. 55 (9): 34–40. arXiv:1607.08011. Bibcode:2017IComM..55i..34A. doi:10.1109/mcom.2017.1600613. hdl:10609/93072. ISSN 0163-6804. S2CID 2798291.
  7. ^ a b "SX1261/2 Datasheet". Semtech SX1276. Semtech. Retrieved 19 November 2021.
  8. ^ "LoRa Modulation Basics" (PDF). Semtech. Archived from the original (PDF) on 2019-07-18. Retrieved 2020-02-05.
  9. ^ M. Chiani; A. Elzanaty (2019). "On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis". IEEE Internet of Things Journal. 6 (5): 772. arXiv:1906.04256. Bibcode:2019IITJ....6.8463C. doi:10.1109/JIOT.2019.2919151. hdl:10754/655888. S2CID 184486907.
  10. ^ Qoitech. "How Spreading Factor affects LoRaWAN device battery life". The Things Network. Retrieved 2020-02-25.
  11. ^ J.C. Liando; A. Gamage; A.W. Tengourtius; M. Li (2019). "Known and Unknown Facts of LoRa: Experiences from a Large-Scale Measurement Study". ACM Transactions on Sensor Networks. 15 (2): Article No. 16, pp 1–35. doi:10.1145/3293534. hdl:10356/142869. ISSN 1550-4859. S2CID 53669421.
  12. ^ "What are LoRa® and LoRaWAN®?". LoRa Developer Portal. Retrieved 7 July 2021.
  13. ^ Mohan, Vivek. "10 Things About LoRaWAN & NB-IoT". blog.semtech.com. Retrieved 2019-02-18.

Further reading

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