LPWA Signal Modelling - LoRa / Sigfox / NB-IoT

IoT / LPWA Coverage Analysis

Whether you're designing an IoT application or building a brand new IoT network, understanding network coverage is essential.

Leveraging years of experience in IoT network technologies R-Spectrum can provide unparalleled insight into IoT coverage and performance. Our team has detailed computer models of Telstra and Vodafone's NB-IoT and LTE-M (eMTC / Cat-M1) networks and can simulate their performance over any geographic area within Australia.

These models are based on true network data, including tower locations, heights, antenna types, azimuth and elevation patterns, power levels, and more. These data are overlaid on high accuracy 5-metre LIDAR, SRTM-1 DEM, and Australian Government Land Cover dataset, providing unmatched simulation accuracy.

In addition to mobile operator IoT networks, R-Spectrum can model class-licensed LPWA technologies such as LoRa and Sigfox. Class-licensed IoT technologies are becoming extraordinarily popular in Australia, notably in the rollout of agricultural "smart-farm" wireless networks. R-Spectrum's LoRa and Sigfox modelling uses the same high accuracy terrain and vegetation datasets to provide IoT network designs that are truly optimised to their physical environment.

LoRa LPWA coverage modelling, NB-IoT desktop study

Technology Comparison

As a recap on IoT technologies, coverage (both geographic and penetrative) is primarily determined by channel size. Channel size in turn defines receiver sensitivity - the smaller the channel, the more sensitive the RF headend can be. When factoring in regulatory transmit power limitations this gives us a working figure for Maximum Coupling Loss (MCL).

The consequence however is that a smaller channel size provides less capacity. When selecting a wireless IoT technology a compromise must be struck between throughput and coverage that balances performance against build cost.

  NB-IoT eMTC (Cat-M1) LoRa Sigfox
Channel Bandwidth 180 kHz 1.08 MHz 125 to 500 kHz 192 kHz
Data Throughput 50 kbps 1 Mbps 50 kbps 100 bps
DL Receiver Sensitivity -141 dBm -109 dBm -132 dBm -129 dBm
Maximum Coupling Loss 165 dBm 155.7 dBm 152 dBm 161 dBm
Duplex HD-FDD FDD / TDD/ HD-FDD HD-FDD FDD
Max. Modulation QPSK 16QAM CSS BPSK

Across the globe Mobile Network Operators have generally implemented both NB-IoT and LTE-M networks, covering off two use cases - long range + low data rate, medium range + medium data rate, respectively.

For companies and individuals, class-licensed technologies (i.e., those that can operate in public-park spectrum) are the only available choices. The two most common are LoRa and Sigfox. Sigfox however requires authorisation to become a geographic region's accredited Sigfox Operator, putting the technology out of reach for most businesses.

This leaves LoRa as the key IoT technology for ad hoc network builds. LoRa provides performance similar to NB-IoT, with a notable reduction in coverage due to the 1 Watt EIRP limit imposed in Australia. In terms of effective range Australian LoRa networks can provide connectivity up to about 15 kilometres, although performance can be highly variable past the 3 to 5 kilometre mark.