Fluctuations of end-to-end delays in low-latency WebRTC-based UAV-borne internet of things operating in an urban environment.

Smart cities, first proposed in the early 1990s, continue to face new opportunities, such as the prevalence of UAVs, and new challenges, such as the need to provide hard real-time communications with UAVs with delays of sub-10-milliseconds and little jitter or even no jitter. Although existing highly reliable, low-latency wireless networks are capable of meeting these challenges, there is a general agreement that classical transport protocols cannot effectively meet such stringent requirements. This paper investigates UAV-borne WebRTC-based IoT for its ability to provide low jitter in an outdoor, highly reliable network environment. The results of field experiments conducted under various network conditions show that WebRTC was able to ensure little fluctuation of end-to-end delays. Moreover, in the case of error-free transmissions, fluctuations were so small that jitter, expressed in milliseconds, was close to zero. The significant advantage of the WebRTC Data Channel over the classic web logical channel, i.e. WebSocket, in terms of jitter was also demonstrated.