Delay Analysis of Multi-Hop Satellite-Terrestrial Networks with Hybrid RF/FSO Links

Industry and academics have shown a strong interest in satellite-terrestrial networks combined with new technologies such as free-space optics (FSO). We propose a downlink satellite-terrestrial network solution combining FSO with site diversity and multi-hop hybrid radio-frequency (RF)/FSO links. Although the proposed network architecture is a cost-effective solution with wide coverage and immunity against different weather conditions, the multi-hop links can degrade its delay performance. Hence, we analyze the network dropping probability and latency to address the hop-count problem for various applications. We validated the derived network performance by Monte-Carlo simulation and showed that this setting could support ultra low latency applications such as medical applications with latency between 3–10 milliseconds, audio/video 2–50 milliseconds, and augmented reality 7–20 milliseconds. Also, the proposed network guarantees 98 % data delivery with 20 nodes.