Automated and remotely optimization of antenna subsystem based on radio network performance

Abstract

3rd generation (3G) radio networks using WCDMA radio access technology will offer the customers services with higher bit rates than in nowadays 2nd generation networks. All users share the same frequency resource, therefore 3G networks are commonly believed to be interference limited. For this reason it is of utmost importance to exploit all possibilities in keeping the interference level as low as possible. One means for this, already used in 2G systems, is adjusting the downtilt of the antennas in a way, reducing the interference transmitted and received as much as possible, still ensuring the required coverage. In earlier studies it has been shown how careful radio network planning already in the preoperational phase can drastically increase 3G network performance. Optimal downtilt was found by applying a constant tilt to all cells in the network. The network consisted only of very high sites and therefore the gains of e.g. 40-50% in capacity were considered to be optimistic. The scope of the simulations for this paper therefore was to evaluate the gains in terms of capacity by optimizing the antenna tilt of WCDMA networks cell by cell in a more realistic environment, showing still gains of up to 20%.