Prediction Model for GSM Signal Attenuation in the Abis Interface during Heavy Rainfall in Nigeria

Abstract

Measurement of Received Signal Levels (RSL) at 13GHz and 15GHz frequencies of Airtel (Nig) ltd GSM Network Microwave link in the A_bis interface were obtained for a period of two years on clear sky and during rainfall events. The analysis of the measured RSL with the link document was used to determine the link worst faded signal during heavy rainfall. The measured RSL based on the link performance analysis were used to determine the rain induced attenuation and it was developed in to empirical models with the extracted rain rate obtained from the Nigerian Meteorological Agency (NIMET). The developed models have mean model error of 0.0019 and a standard deviation of 0.0043 at 13GHz. While at 15GHz the mean model error and standard deviation were 0.0108 and 0.0245 respectively. These predictions showed that the ITU-R model under estimated rain induced attenuation at 0.1% and 0.01% time of the year. It also suggested compensation factors of 11.35dB at 13GHz and 18.78dB at 15GHz to be added to the link path loss.