The effect of rain attenuation on S-band terrestrial links

Past studies have established that in the S-band range of 2GHz, rain attenuation is negligible. However, every year, heavier rain intensities are being experienced in tropical countries like Malaysia due to current global warming conditions. The study presented in this paper aims to quantify the rain attenuation that is suffered by Worldwide Interoperability for Microwave Access (WiMAX) signals in the 2.3GHz in medium city and suburban environments in some parts of Malaysia. The Received Signal Strengths gathered in field experiments were used to calculate the rain attenuation in dB/km in various rain rates. The results show that in suburban environment, the rain attenuation was calculated to be 0.22dB/km at a rain rate of 65.4mm/hr. In medium city environment, the rain attenuation was calculated to be between 0.1958dB/km and 0.2676dB/km for rain rates between 70.2mm/hr to 74.7mm/hr. Wet foliage tends to increase Radio Frequency signal absorption. Therefore, the study findings may be significant in the planning of WiMAX and Long Term Evolution link-budgets, especially if wide-range coverage is envisioned in rural areas.