Reliability Assessment of a Base Transceiver Station Using 2-Parameter Weibull Distribution Method

Abstract

About 80% interruptions of cellular network availability occur due to power outage on BTS stations and reliability analysis of these systems is yet to receive exhaustive studies. Most network providers solely depend on generating power on their BTS sites using diesel generators since the grid power is least reliable, but the frequency of power outages from the diesel generators is alarming, hence, the need to analyse the reliability of these generators and their maintenance routine in relation to the site availability.
 In this study, the reliability of a Base Transceiver Station (BTS) is assessed by analysis of data obtained within a period of six months from four BTS sites used as case study using 2-parameter Weibull failure distribution method. The failure times of each BTS site were rank-ordered and the estimates of Weibull parameters θ and β were obtained from Weibull least-squares plots.
 The Weibull plots for the four BTS sites had a good index of fit which shows that a strong linear relationship exists. The value of the shape parameter (β) was found to be between the range of 1< β < 3 for all the BTS sites studied. This means that the probability density function is skewed and the failure rate of the BTS sites is increasing. The reliability of each BTS site was successfully computed. The reliability of the four BTS sites was found to be increasing as their values of scale parameter, θ increases. From the results obtained, BTS site RV0144 had the highest reliability while BTS site RV0248 had the lowest reliability.