Modelling the impact of antenna installation error on network performance

Abstract

This dissertation models the impact of antenna installation errors on network perfor-mance of a Long Term Evolution (LTE) site. To test the impact of antenna installation parameters (antenna height and mechanical tilt), simulations were done on different LTE sites situated in specifically chosen environments with a variety of terrain heights. This enables the correlation of the site coverage with terrain height variation in order to see how the installation parameters influence coverage of sites in different locations. Coverage results derived from the developed Matlab simulation were verified and val-idated by commercialised software (CHIRPlus BC) to ensure that the methods used are correctly implemented to obtain valid results. Using statistical analysis, the verified re-sults enabled us to calculate tolerances for the installation parameters, taking terrain height variation into account. The statistical analysis was an important step towards understanding the extent of the impact of practice on the adjustments. Given the results obtained from the statistical analysis, it was found that a minimum tilt adjustment error of 0.5◦ can have an impact of 7% on coverage. A minimum height adjustment error of 2 m has an impact of 6% on coverage. A parameter called effect size was used to describe the practical significance of the impact of the antenna installation errors. It was found that a minimum tilt adjustment error of 3◦ has a high effect size and can therefore have a significant practical effect on coverage. Height adjustment errors do not have the same amount of practical impact as tilt adjustment errors where a practical effect on coverage is only observed when height adjustment errors exceed 2 m. It was also found that the Terrain Roughness Factor (TRF) cannot be used as a good predictor for coverage, but effective height can.