| 摘要 |
Whether or not two vehicle components 10,12 (e.g. train carriages) are physically coupled is determined by transmitting signals 18 between the two components. The signals 18 are used to determine the distance between the two components. If the two components are physically coupled, a wireless network connection (e.g. IEEE 802.11a) may be established between them using wireless transceivers 16. The signals 18 may be ultrasonic ranging signals, or signals transmitted by the wireless transceivers. Alternatively or additionally, the wireless transceivers on each vehicle component transmit signals having a field strength which is greater in a direction parallel to the longitudinal axis of the vehicle component than in a direction perpendicular to the longitudinal axis. If a connection is established between the two components, a signal containing identification information is transmitted from one component to the other. Unwanted wireless connections are therefore not established between train carriages which do not form part of the same train, for example train carriages located on an adjacent track or belonging to different train companies. |
