Verification Measurements of Mechanical Downtilt in WCDMA

The target of this paper is to analyze the impact of antenna mechanical downtilt in WCDMA through field measurements, and to evaluate the capacity gain in the downlink The measurement campaign was performed in a pre-commercial urban UMTS network consisting of macrocells and microcells. Firstly, the field, trials were conducted, in a network with part of the antennas mechanically downtilted. Thereafter, mechanical downtilt angles were removed, and the corresponding measurements were performed again. For both network configurations, two different traffic load situations were measured in order to be able to estimate the downlink capacities. The measurement results verify the increasing impact of mechanical antenna downtilt on the downlink capacity, which has been earlier observed with simulations. The capacit gain of 20% can be achieved through reduction of other-cell interference. Moreover, pilot polluted areas that affect the functionality of the network can be also reduced in practice with downtilt.