Cell Breathing and Coverage Prediction in WCDMA

Cell breathing technique is commonly used in cellular network such as Wide Code Division Multiple Access (WCDMA) to overcome load congestion by expanding or shrinking the cell coverage. This paper presents the study of the cell breathing boundary of urban environment for WCDMA. The base station cell coverage may expand or shrink depending on the number of mobile station being served. The COST231 HATA model is used in this study to predict the cell coverage for urban environment. The actual received signal strength indicator (RSSI) obtained by conducting drive test measurement are compared to the received signal code power (RSCP) of the COST231 HATA propagation model. The error calculated in the measurements enables to determine the minimum discrepancy between RSSI and RSCP data. Thus the COST231 HATA model can be used to predict correctly the cell coverage for urban environment. The result also shows that during light load the cell coverage radius is 0.18 km and then decreases to 0.15 km so as to limit soft handover and hence reduces load congestion.