“…The transmission range is extended by a factor of (2.9 to 1.7) km when the QAM-16 modulation is employed in composite (HG00 + HG01) mode and transmitted in the same weather conditions with the tolerable bit error rate (BER) of 10 −5 . In 2022 [21], by using optical links in the turbulent atmosphere, the authors investigated a RF carrying signal for dual hop FSO/RF links of 500 m/50 m. The author analyzed Gamma-Gamma (G-G) and Lognormal (LN) models and achieved a BER of 10 −6 . In 2022 [8], clear, haze, rain and fog conditions with attenuation losses of 0.2 dB km −1 , 2.3 dB km −1 , 4.3 dB km −1 and 8 dB km −1 have been considered for the performance enhancement in the link range of about 46.1%, 35%, 29.4% and 25.9%, respectively.…”