LPWAN – Quantifying LoRA

Cisco LoRA Industrial Router

Cisco LoRA Industrial Router

About LoRa

LoRa (an abbreviation for… Long-Range) is a wireless infrastructure technology for the IoT, targeting deployments where:

  1. end-devices are typically battery powered,
  2. end-devices do not need to transmit more than a few bytes at a time, and
  3. data traffic can be initiated either by the end-device (such as when the end-device is a sensor), or by an external entity wishing to communicate with the end-device (such as when the end-device is an actuator).

The long-range and low-power nature of LoRa makes it an interesting candidate for smart sensing technology in civil infrastructures (such as health monitoring, smart metering, environment monitoring, etc.) as well as in industrial applications.

LoRa can commonly refer to two distinct layers:

  1. the physical layer using Chirp Spread Spectrum (CSS) radio modulation technique, and
  2. a MAC layer protocol (LoRaWAN) — although the LoRa communications system also implies a specific access network architecture.

The basic architecture of a LoRaWAN network is as follows: end-devices communicate with gateways using LoRa with LoRaWAN. Gateways forward raw LoRaWan frames from devices to a network server over a backhaul interface with a higher throughput, typically Ethernet or 3G. Consequently, gateways are only bidirectional relays, or protocol converters, with the network server being responsible for decoding the packets sent by the devices and generating the packets that should be sent back to the devices.

lora_network

LoRa Network Architecture

Motivation

LoRa is advertised as one of the key technologies to enable the “Internet of Things” – indeed, is often advertised as “being to the IoT as WiFi was to home networking: – by providing:

  • A “star-of-stars” network topology
  • Long range, up to 15 km
  • Long battery life, over 10 years
  • Operation on unlicensed spectrum (433-, 868- or 915-MHz ISM bands)
  • High link budget, up to 157 dB
  • Low infrastructure cost and low end-device cost

However, literature is sparse with anything other than marketing material. Indeed, very little independent research has been published on LoRa. Being the “sceptic academics”, our current goals for our work with LoRa include:

  • Quantifying LoRa technology, including its transmission range, capacity, power consumption, MAC protocol performance, etc.
  • Based on the measurement and observation obtained, proposing new mechanisms to improve the performance of LoRa.

Publications

Augustin, Aloys; Yi, Jiazi; Clausen, Thomas; Townsley, Mark W

A Study of LoRa: Long Range & Low Power Networks for the Internet of Things Journal Article

MDPI Sensors, 16 (9), pp. 1466, 2016, ISSN: 1424-8220, ((5 yr Impact Factor: 2.437)).

Abstract | Links | BibTeX

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