Design of a multi-hop ad-hoc outdoor wireless sensor network

Abstract

ENGLISH ABSTRACT: Currently the inability to monitor rhino and other endangered animal species in real time is hindering the e ort to reduce poaching. This thesis proposes a multi-hop adhoc wireless sensor network (WSN) to deliver behavioural and positional data from an on-animal tag to a database in real-time. After practical testing, a LoRa capable radio frequency module operating at a frequency of 433 MHz was chosen. Each WSN node is power-aware and sustains its battery with energy harvested from solar radiation. A multi-hop ad-hoc routing protocol routes communication from an on-animal tag to the nearest server node. WSN nodes can detect breaks in a communication route and can request an alternative route on demand. During practical testing over a 45 km route with 3 WSN nodes, an on-animal tag mounted at rhino ear-height and ankle-height was able to successfully communicate 92.5% and 64.6% of messages respectively. A server node received 96% of communication from an on-animal tag, routed through 2 WSN nodes which were spread over 14 km. The report concludes by detailing improvements and future work to the research project before it could be commercially viable.

AFRIKAANSE OPSOMMING: Wildbewarings veldtogte word tans belemmer deur tegnologiese tekortkominge wat verhoed dat bedreigde spesies intyds bewaak en beskerm kan word. Hierdie tesis vervat `n omskrywing van die navorsing wat gedoen is om `n koordlose veelsprongige ad-hok bewakingsnetwerk (WSN) te ontwikkel en te implementeer wat ten doel is om liggingsinligting van `n op-dier-toestel intyds na `n databasis te versend. Na aanleiding van praktiese eksperimente is die stelsel met `n 433 MHz LoRa radiomodule bewerkstellig. Elke bewakingsnetwerknodus is kragstandbewus en onderhou sy eie battery met energie wat vanaf die son opgewek is. `n Veelsprongige ad-hok herleidingsprotokol herlei boodskappe vanaf die op-dier-toestel na die naaste bedieningsnodus. Indien `n bewakingsnetwerknodus `n onderbreking in versendingsroete identi seer, kan `n alternatiewe roete aangevra word. Praktiese eksperimente is met 3 bewakingsnetwerknodusse en `n op-dier-toestel teen renosteroorhoogte en -enkelhoogte uit gevoer. Daar was bevind dat 92.5% van alle boodskappe teen renosteroorhoogte en 64.6% van alle boodskappe ten renosterenkelhoogte suksesvol versend is. `n Bedienernodus was in staat om 96% van die boodskappe wat deur twee bewakingsnetwerknodusse herlei was te ontvang. Die bewakingsnetwerknodusse was oor `n bereik van 14 km uit mekaar uit versprei. Die tesis sluit af met voorstelle oor toekomstige verbeteringe wat bewerkstellig sal moet word voordat die stelsel handelsgeregtig sal wees.