Generation of Pathloss and Interference Maps as SON Enabler in Deployed UMTS Networks

In modern cellular systems such as HSPA and LTE, link- and cell level performance has largely been optimized. This is less true for performance on inter-cell level where antenna parameters and new site locations are set based on expensive and limited drive tests and inaccurate propagation models. Since the 3G ecosystem already provides devices for data collection at the radio network controller, RF optimization tools, and remotely configurable antennas, the missing component and the focus of this paper is the conversion of collected data into useful input for RF optimization tools. In particular, we propose to position measurement report messages sent from terminals to radio network controller for active set management to generate accurate pathloss, interference, and demand maps. To evaluate if the presented positioning scheme is sufficiently accurate, all antennas of a network are turned in a simulation to obtain the CDFs of errors in predicted antenna gain changes caused by positioning errors. The data indicates that the positioning accuracy is sufficient for 3 sector deployments. To support the deployment of micro- and picocells as well as higher order sectorization, ideas to enhance the positioning scheme are outlined.