A data communication system (DCS) connects moving trains to wide area networks, allowing communication between onboard applications and ground infrastructure regardless of the position of the train. A DCS must be protected by strong security measures to prevent unauthorized access, but this poses a problem for network engineers. When traveling at high speeds the train may only connect to a particular wayside AP for a few seconds, so handover times must be extremely fast. Handoffs that take more than 100 ms may cause critical data loss, but strong security systems require time to negotiate new connections. This is the challenge networking engineers face in the bid to establish uninterrupted, reliable communications for moving trains.
