Abstract Pilot pollution interference is a fresh research direction in a typical W-CDMA based system such as Universal Mobile Telecommunication System (UMTS). The objective of the study is to quantify the impact of pilot pollution interference effect on UMTS radio network coverage quality. An innovative approach is proposed to detect any excess of pilot pollution interference beyond limits, which leads to coverage shortage or gaps. An immediate false alarm signal will be sent to the network operator indicating a need for a corrective action. The proposed approach is investigated and compared with the existing approaches. In addition, a new concept called one sigma visualization device is introduced to help with evaluating the proposed approach. Although the proposed approach aims to assist the network operator picturing and managing the network performance, it is also used in the early life cycle of network planning. Experiments on a real world-planning task show the feasibility and effectiveness of the proposed approach.