Ultra-Reliable IoT Communications with UAVs: A Swarm Use Case
UAVs are powerful IoT components, offering sensing, communications and data analysis in the air. Recently, 3GPP TS 22.261, TR 22.862, and TR 36.777 have specified performance requirements for communications between multiple UAVs in the 5G domain. This article discusses communications reliability challenges in a UAV swarm context. Recommendations for designing an ultra-reliable communications system for UAV swarms are introduced with a focus on the software protocol stack and RF hardware. For the purpose of demonstration, we developed Easy- Swarm, an open-source UAV swarming platform that adopts the LoRa radio at the physical layer and a low-latency channel access protocol at the MAC layer. Real-life testbeds are built consisting of 10 UAVs and 20 robotic cars that produce background traffic. LoRa, WiFi and LTE networks are employed to provide broadband and cellular wireless network support. Results show that using LoRa leads to better reliability, in particular allowing for higher swarm density and longer coverage distance, than when WiFi is used. In addition, LTE provides the best reliability and latency for UAV swarms with good network connectivity.