Patent ID: 7813699

Claim:
An electronic toll collection system for conducting toll transactions with vehicle-mounted transponders travelling in a multi-lane roadway, the electronic toll collection system comprising: one or more antennas for engaging in RF communications with transponders, each antenna defining a capture zone in a portion of at least one lane of the multi-lane roadway; two or more RF transceivers, each RF transceiver having an RF port; a switching network connected to the antennas and to the RF ports of the transceivers, the switching network selectively connecting at least one of said transceivers to at least one of said antennas; a controller for controlling the switching network and the transceivers; and failure detection circuitry connected to the RF ports of the transceivers for detecting whether any of the transceivers output an RF signal having a power level below a threshold level, the failure detection circuitry providing a result signal to the controller, whereby the controller is configured to control the switching network to connect the antennas to the transceivers in accordance with a scanning pattern, and wherein the controller is configured to cause the switching network exclude one of the transceivers if the result signal from the failure detection circuitry indicates a failure in said one of the transceivers.