Abstract: A transponder formed on a circuit substrate having a longitudinal axis and a transverse axis. An antenna is disposed on one side of a transverse axis, extending in a longitudinal direction, and the remaining circuit components are disposed on the other side of the transverse axis. The remaining circuit components may include a controller, an RF transceiver, and a battery. A ground plane defines an antenna space within which the antenna is disposed.

Abstract: A method and system for obtaining traffic information regarding the travel time between two points using vehicle-mounted transponders. The system includes an upstream reader and a downstream reader. The upstream reader inserts a time stamp into a passing transponder. The downstream reader reads the time stamp and determines the travel time between the two readers. The downstream reader may accumulate a number of travel times from multiple transponders and calculate an average travel time. The downstream reader may then send the calculated travel time to a display sign for display to motorists. The displayed travel time may include a quantitative value or a qualitative assessment of the travel conditions.

Abstract: 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.

Abstract: An electronic toll collection system that includes a reader with internal monitoring circuitry. The reader includes a controller and transceiver, which is connected to an antenna, wherein the transceiver sends outgoing RF signals to the antenna and receives incoming RF signals from the antenna. The reader includes transceiver monitor circuitry for monitoring the characteristics of the RF signals to assess transceiver performance. The transceiver monitor circuitry provides a result signal to the controller. The controller may adjust the operation of the transceiver through adjustments to an adjustable element based upon the measurement signals. The controller may also send measurement information to a remote computer and receive instructions from the remote computer, thereby enabling remote monitoring and adjustment of the electronic toll collection system.

Abstract: A method and system for adaptively allocating bandwidth in an electronic toll collection system. The system includes a reader that adapts the scanning time allocated to specific antennas based upon the traffic conditions. Those antennas that process a higher volume of traffic receive a greater allocation of the scanning time. In some embodiments, the determination as to when to allocate additional time to an antenna may be based upon whether or not a transponder is currently in the coverage zone for the antenna.

Abstract: An electronic toll collection system with dynamically adjusted timing for operation of one or more subsystems. The timing is dynamically adjusted based upon the prevailing traffic speed for the roadway. The roadway traffic speed is determined based upon direct measurements of traffic speed by external equipment or based upon a variable correlated with traffic speed. The variable may include the average number of handshakes per transponder over an estimation period. The subsystem may include a vehicle position determination system, an enforcement system, a loop detection system, or other such subsystems.

Abstract: A retail package for an activated transponder that prevents the transponder from receiving or responding to interrogation signals from a reader as the packaged transponder is shipped to retail outlets or while the packaged transponder in the possession of a retail purchaser but prior to the purchaser's intended use. The retail packaging includes shielding material to attenuate RF transmission sufficiently to prevent the accidental occurrence of a transaction, such as a electronic vehicle toll transaction. Once the transponder is removed from the packaging it may function normally.

Abstract: An improved electronic toll collection system having two lane-based antennas per laneway. The antennas include an overhead antenna and a side mount antenna. The side mount antenna is disposed so as to communicate especially with license plate transponders. The two antennas are coupled to a transaction processing system for conducting toll transaction communications with a vehicle-mounted transponder through one of the two antennas.