Comtest Wireless is a VIAVI Solutions company. We are world experts at providing proven testing and measurement solutions for GSM-R telecommunications networks and ERTMS signalling systems. Our customers are vendors and operators of GSM-R communication and ERTMS signalling systems. These include rail operators, telecom operators, equipment vendors and government agencies. Our state-of-the-art active and passive monitoring solutions are underpinned by over 10 years’ expertise and experience in railways, signalling, telecoms and IT. These unique test and measurement solutions provide our customers with the capability to collect data and monitor communications from multiple sources, vendors and types of equipment.