A data transmission system for a track-bound transport system has a plurality of vehicle-mounted optical transmitting/receiving devices, or transceivers, on at least one vehicle. The devices are oriented perpendicular to the direction of travel towards both sides of the vehicle. Trackside-mounted stationary optical transceivers are arranged along a route to be travelled by the vehicle on the side of the travel route. The vehicle-mounted optical transceivers is configured to communicate at least with the trackside-mounted stationary optical transceiver positioned the closest thereto and to independently maintain separate communication links at as full a bandwidth as possible with one of the trackside-mounted stationary optical transceivers. There is also described a track-bound transport system and a method for transmitting data between a vehicle and a stationary network.