LoRa Communications as an Enabler for Internet of Drones towards Large-Scale Livestock Monitoring in Rural Farms

2021

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Figure 15. 

Aerial view of the location (Cyberjaya, Malaysia) for drone speed measurement. 

Data from the EN were transmitted every 5 s, while data were received by the GW 

every 9 and 7 s for the case of SF12 and SF7, respectively. The difference in time required 

to receive data in SF12 and SF7 is due to the on-air time, as SF12 on-air time is longer than 

SF7. In addition, the drone flew at different speeds with a ±5 km/h variation due to un-

predictable wind direction during measurement and a fixed altitude of 100 m above the 

ground. 

Figure 16 shows the percentages of packet delivery at different speeds for SF12 and 

SF7, which are 100% and 77.27% (on average), respectively. Results show the robustness 

of SF12 towards the Doppler effect, while SF7, on the other hand, is proven to be sensitive 

to the drone speed, especially at a speed of 35 km/h and above. This measurement offered 

a new insight into the performance of LoRaWAN

®

-based aerial communication because 

the previous study in [46] was limited to 50 km/h.