GovWire

This report investigates 2G, 3G, 4G and millimetric-wave signal propagation loss within rail tunnels and how to determine the optimal way to address in-tunnel connectivity.

This research examines qualitative tunnel signal propagation principles through literature review and desktop radio frequency modelling. It compares these to those obtained from radio frequency test measurements and associated signal propagation loss at three non-operational tunnels.

This research is to help the rail and mobile industries predict the signal propagation characteristics of any tunnel and determine the most appropriate technical solution, taking into consideration:

• the wireless technology type
• tunnel characteristics (such as length and construction)
• cost
• passenger or operational needs