Performance Analysis of Space-Air-Ground Integrated Networks of FSO/THz/RF Multi-Band Communication

We propose using the Poisson point process (PPP) for accurate modeling in Space-air-ground integrated networks (SAGIN). SAGIN is experiencing significant growth, aiming for ultra-fast speeds, low latency, and integration of AI, IoT, and other emerging technologies. To achieve better performance than existing hybrid bands in SAGIN, we utilize three distinct frequency bands—Radio frequency (RF), Terahertz (THz), and Free-space optical communication (FSO)—to compensate for their shortcomings effectively. Then, we derive not only the coverage probability but also the rate coverage probability formula of the network and utilize Newton's method to deduce the most optimal channel allocation scheme. Moreover, we use comparison experiments between different frequency bands, altitudes, and other conditions to affirm its reliability and effectiveness in advancing SAGIN coverage and rate coverage probability. The results show that our proposed scheme performs up to 3 times better than a single-spectrum scheme and 2 times better than the existing mixed method.