Abstract: A system for transmitting data between a rotating system and a stationary system. This system has a patch antenna affixed to the surface of a rotating body. A transmitter splits an RF signal into n identical RF signals. The n RF signals are phase shifted to have phases that are 360 divided by n degrees apart. The RF signals are then sequentially applied to the n patch antennas which broadcast the RF signals. A stationary receive antenna receives broadcast RF signals from one of the n patch antennas at a time. As a first antenna rotates out of range of the receive antenna, second antenna rotates into range. The phase shift between the RF signals broadcast between from the first and second antenna assures that data is not lost as the rotation occurs.

Abstract: The present mobile wireless local area network system for automating fleet operations creates a short-range wireless local area network (wireless LAN) on a transportation vehicle, such as a: trailer, container, railroad car, ship, or the like. The mobile wireless LAN couples data to a LAN hub from a plurality of wireless sensors that are placed in various locations on the transportation vehicle and on the cargo that is contained in the transportation vehicle. The collected data represents various environmental and functional measurements associated with the transportation vehicle and the cargo. The mobile wireless LAN travels with the transportation vehicle and can interact with a hub on other compatible wireless LANs or wireless interfaces on the hub of a wireline-based LAN that are within data signal transmission and reception range.

Abstract: An interrogation system for enabling transmission and/or reception of RF signals by a communication system. In accordance with the present invention, an interrogation is performed between a transceiver and an antenna prior to the transceiver transmitting or receiving RF signals via the antenna. The interrogation is used to determine whether the antenna transmits and/or receives RF signals having the power and/or frequency band required by the transceiver. The interrogation is performed by an interrogating device transmitting an interrogation signal to the other, responding device. The responding device transmits a response signal to the interrogating device in response to receiving the interrogation signal. The interrogating device determines if the response signal has a predetermined characteristic. If the response signal has the predetermined characteristic, transmission and/or reception of RF signals is enabled.