Systematic literature survey: applications of LoRa communications

Abstract

LoRa is a communication scheme that is part of the low power wide area network (LPWAN) technology using ISM bands. It has seen extensive documentation and use in research and industry due to its long coverage ranges of up-to 20 km or more with less than 14 dB transmit power. Moreover, some applications report theoretical battery lives of up to 10 years for field deployed modules utilising the scheme in wireless sensor network (WSN) applications. Additionally, the scheme is very resilient to losses from noise, as well as bursts of interference through its forward error correction (FEC) scheme . Our objective is to systematically review the empirical evidence of the use-cases of LoRa in rural landscapes, metrics and the relevant validation schemes. In addition, the research is evaluated based on (i) mathematical function of the scheme (bandwidth use, spreading factor, symbol rate, chip rate and nominal bit rate) (ii) usecases (iii) test-beds, metrics of evaluation and (iv) validation methods. A systematic literature review of published refereed primary studies on LoRa applications was conducted using articles from 2010-2019. We identified 21 relevant primary studies. These reported a range of different assessments of LoRa with 10 out of 21 reporting on novel use cases. The authors conclude that more work is needed in terms of field testing, as no articles could be found on performance/deployment in Botswana or South Africa despite the existence of LoRa networks in both countries. Thus researchers in the region can research propagation models performance, the energy efficiency of the scheme and MAC layer as well as the channel access challenges for the region.