Fade Slope Prediction Model for Rain Storms over Sub-tropical Africa

Wireless communication link designers are greatly concerned with design of links that are efficient and readily available. Wireless links operating at microwave and millimetre wave bands, especially in the tropics, are greatly affected during periods of intense rainstorms and hence measures need to be taken to counter these effects. Dynamic rain fade mitigation techniques such as adaptive coding and modulation (ACM) are commonly employed to improve on link performance. The knowledge of fade slope becomes an important input in the design of these rain fade mitigation schemes. In this study, an investigation is carried out on rain fade slope statistics using a two-year data collected over Durban, South Africa [29°52'S, 30°58'E]. Results of this study reveal that rain fade slope increases with an increase in the attenuation threshold and rain fade slopes of 0.9179 dB/s and above are possible for rainstorms occurring with rain rates equal to or greater than 150 mm/h.