The impact of electromagnetic disturbances in the railway signalling systems was investigated. This Project required a holistic approach and a solid experience in various fields, such as railway environment, signalling systems, telecommunications and Electromagnetic Compatibility (EMC). The main goal of this Project was to establish the relationship between the threats caused by electromagnetic interferences and the quality of the service (QoS) and/or other KPIs relevant for Railway Control and Signalling Systems (RCSS).