An optimal commercially available wireless sensor network in viticulture

Abstract

For more than a decade research in wireless sensor networks has received much attention. Several wireless sensor network standards have been proposed and are still being developed. In precision agriculture, specifically viticulture, wireless sensor networks have been proven as advantageous, but widespread implementation of such systems is still lacking in the South African wine farm industry. Investigating what the specific requirements of a wireless sensor network for a South African viticulturist are, and assessing the existing commercial systems available, can provide better insight into the reason for their slow implementation. The researcher has identified a feasible commercially available system and by using the identified requirements, proposes a system as an optimal solution for wireless sensor networks to be implemented at a South African wine farm. The cost of the sensor systems is the most important factor for a wine farmer. This challenges the design paradigm of wireless sensor networks, where nodes are deployed in redundant fashion to create a network of nodes capable of routing packets over several different routes to the same destination. The focus shifts to deploying nodes more sparsely, capable of greater communication distance. Thievery is of concern as well and poses the problem of increasing the risk of theft by installing sensors within line of sight together with solar panels. Placing the nodes on the ground, out of sight, causes interference with the radio signal and reduces the communication distance drastically. Since solar panels are not feasible due to theft, batteries will have to last at least one season. The DASH7 wireless standard meets the longer communication distance and extended battery life requirements, and coupled with autonomous quadcopters is a promising optimal solution. Nodes will not have to be in line of sight since the drone flies directly overhead and initialises communication to retrieve the sensor data. The BLAST principle that the DASH7 standard uses fits in with this approach and should be investigated more thoroughly, but commercial implementation of it has to wait until the development of the standard is completed.

Vir meer as n dekade het navorsing in draadlose sensor-netwerke heelwat aandag ontvang. Verskeie draadlose sensor-netwerk standaarde is voorgestel en is steeds onder ontwikkeling. In presisie-landbou, spesifiek wingerdbou, is draadlose sensor-netwerke reeds as voordelig bewys. Die wydverspreide implementering van sisteme van so aard in die Suid-Afrikaanse wynbedryf lei egter steeds gebrek. Die spesifieke behoefte aan n draadlose sensor-netwerk vir n Suid-Afrikaanse wingerdboer, asook die waardebepaling van kommersiële sisteme wat tans beskikbaar is, is ondersoek, om sodoende beter insigte te verskaf rakend die redes vir die stadige implementering daarvan. n Uitvoerbare kommersieel-beskikbare sisteem is geïdentifiseer en deur gebruik te maak van die geïdentifiseerde vereistes is n sisteem voorgestel wat as optimale oplossing vir draadlose sensor-netwerke vir n Suid-Afrikaanse wynplaas kan dien. Die koste van sensor-sisteme is die belangrikste faktor vir n wynboer. Dit veroorsaak teenstrydigheid met die ontwerp-paradigma van draadlose sensor-netwerke waar nodusse in n oorbodige wyse geïnstalleer word. Gevolglik word n netwerk geskep waar nodusse in staat is om pakkies via verskeie roetes na n eindbestemming te kan stuur. Die fokus verskuif daarna om nodusse eerder yl te installeer met groter kommunikasie-afstande tussen in. Diefstal is ook n bekommernis en die installasie van sigbare sensors en sonpanele word dus n hoër risiko. Die installasie van die nodusse op die grond en buite sig, veroorsaak steurings in die radio sein en gevolglik word die kommunikasie reikafstand drasties verminder. Omdat die installasie van sonpanele buite die kwessie is, moet n battery se leeftyd ten minste een seisoen duur. Die DASH7 draadlose standaard voldoen aan die vereistes vir n langer kommunikasie-afstand en verlengde battery-leeftyd. Die verbinding daarvan met die outonoom vier-propeller helikopters beloof om n optimale oplossing daar te stel. Nodusse kan dus buite sig geïnstalleer word, met die robotvliegtuig wat direk bo-oor vlieg en kommunikasie bewerkstellig om sodoende die sensor-data te onttrek. Die BLAST beginsel wat deur DASH7 gebruik word, pas in by dié benadering en behoort in meer diepte ondersoek te word. Tog kommersiële implementering daarvan sal moet wag totdat die ontwikkeling van die standaard voltooi is.