Patent attributes
An electronic toll collection system wherein the reader includes a switching network and a plurality of transceivers operating under the control of a controller. The reader further includes failure detection circuitry for determining whether any of the transceivers have failed based upon the RF outputs of the transceivers. If the controller determines that a transceiver has failed, then it alters the switching pattern such that the switching network excludes the failed transceiver from being connected to the antennas. The reader thereby provides for adaptive RF channel assignment, as the particular transceiver used to excite a particular antenna may be dynamically altered, and the provision of at least two transceivers in the reader ensures transceiver redundancy.