LoRaWAN Spreading factor, range, data rate in LoRa System
This page describes LoRaWAN Spreading factor, range and data rate used in LoRa System. The table and formulas for relation between Spreading factor vs distance range vs data rate are mentioned.
These terms are related to each other and they are explained below. The terms are associated with chirp spread spectrum (CSS) modulation technique. It uses wideband linear frequency modulated chirp pulses in order to encode baseband information.
Chirp Spread Spectrum is used in space and military communications due to its long range, low transmit power and less interference.
LoRaWAN Spreading Factor
LoRa Modulation in LoRaWAN uses chirp spread spectrum for encoding. Here, each bit is spread by chipping factor. The number of chips per bit is known as spreading factor. In other words, the duration of chirp is known as spreading factor.
CSS uses spreading factors from 7 to 12. The spreading factor for various regions across the world are mentioned in the following tables. As mentioned small spreading factors offer high bit rate or LoRaWAN data rate and need less OTA (Over The Air) time. Large spreading factors offer low data rates and need more over the air time.
LoRaWAN spreading factor and data rate in Australia
LoRaWAN spreading factor and data rate in Europe
LoRaWAN spreading factor and data rate in USA
LoRaWAN spreading factor and data rate in INDIA
In the table "RFU" refers to "Reserved for Future Usage".
LoRaWAN Range or distance
The range is the distance covered by LoRaWAN signal to serve multiple end devices from single tower. From following equation of free space path loss, LoRaWAN range can be easily derived.
As per one experiment, LoRaWAN range (i.e. distance) of 702.676 km was achieved using only 25 mW (i.e. 14dBm) of transmit power across border of Germany. The LoRaWAN gateway is installed at the height of 30 meters.
LoRaWAN Data Rate
As we know, data rate refers to rate at which data is transmitted from one one end to the
other through wired medium or wireless medium.
➨ Data rate = Number of bits transferred / Total time taken for transfer
Different wireless technologies will have data rate range different based on their physical layer parameters (modulation, code rate etc.) and radio parameters (bandwidth, number of carriers etc.) . LoRaWAN is also a wireless system. The LoRaWAN data rate depending on Spreading factor, Bandwidth and code rate as per equation mentioned below.
LoRaWAN data rate vs Spreading Factor conversion calculator
Following equation mentions relation between LoRa data rate, LoRa spreading factor, Code Rate and Bandwidth.
Refer LoRa calculator >> which mentions calculation of LoRaWAN data rate as per LoRaWAN spreading factor entered along with code rate and bandwidth.
LoRaWAN related links
The LoRaWAN Wireless tutorial covers following sub topics:
LoRaWAN Smart Parking LoRaWAN sensor design LoRaWAN smart healthcare system LoRaWAN smart water metering LoRaWAN architecture LoRaWAN Interface Types LoRaWAN roaming types LoRa tutorial LoRa Frequency Bands LoRa protocol stack LoRa MAC layer LoRaWAN classes LoRa features LoRa Transceiver module