Radio frequency highway management system
First Claim
1. In a highway toll collection system where normal transponders carrying specific vehicle identification information are carried on motor vehicles and communicate with a roadside radio frequency (RF) system,said normal transponders being actuatable by a signal from the roadside RF system to record the address of the roadside system at the transponder and transmit the transponder identification information, including a selected class of vehicle, to the roadside RF system, the improvement comprising:
- a monitor transponder located to receive a detection signal from the roadside RF system;
said roadside RF system including receiving means responsive to the transmission of said specific vehicle information from the normal transponder and including means for sending said detection signal to said monitor transponder thereupon; and
said monitor transponder including means responsive to said detection signal to emit a sensible signal upon receipt of said detection signal.
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Accused Products
Abstract
Traffic management or enforcement is performed through the use of a monitor transponder in the environs of an RF highway toll collection system. When normally operating transponders communicate with a roadside reader system, the roadside system communicates with the monitor transponder, which in turn signals if a valid normal transponder is detected. If no signal is generated by the monitor transponder, it is evident that the vehicle has no transponder or that the transponder is faulty or invalid.
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Citations
10 Claims
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1. In a highway toll collection system where normal transponders carrying specific vehicle identification information are carried on motor vehicles and communicate with a roadside radio frequency (RF) system,
said normal transponders being actuatable by a signal from the roadside RF system to record the address of the roadside system at the transponder and transmit the transponder identification information, including a selected class of vehicle, to the roadside RF system, the improvement comprising: - a monitor transponder located to receive a detection signal from the roadside RF system;
said roadside RF system including receiving means responsive to the transmission of said specific vehicle information from the normal transponder and including means for sending said detection signal to said monitor transponder thereupon; and
said monitor transponder including means responsive to said detection signal to emit a sensible signal upon receipt of said detection signal. - View Dependent Claims (2, 3)
- a monitor transponder located to receive a detection signal from the roadside RF system;
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4. In a highway toll system wherein toll information is exchanged between transponders in vehicles and a roadside radio frequency (RF) system the improvement comprising:
- the transponders including means for providing a sensible indication responsive to an RF detection signal from the roadside RF system;
preselected ones of said transponders being designated monitor transponders having a specific identification code; andthe roadside RF system including means for determining if preselected toll information is received from the transponders and if so, transmitting a detection signal to the transponders having said specific identification code. - View Dependent Claims (5, 6, 7)
- the transponders including means for providing a sensible indication responsive to an RF detection signal from the roadside RF system;
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8. Apparatus for monitoring normal transponder bearing vehicles in a highway toll collection system where said normal transponders carry transmissible data in memory defining one or more characteristics, the apparatus comprising:
- a roadside RF system which receives transmissible data from said normal transponders;
a monitor transponder for location within the communication range of said roadside RF system capable of providing a sensible signal in response to a detection signal from said roadside RF system; and
means associated with said roadside RF system, conditional on detection of at least one selected characteristic from data transmitted by a said normal transponder, for transmitting a detection signal to said monitor transponder causing provision of a sensible signal. - View Dependent Claims (9)
- a roadside RF system which receives transmissible data from said normal transponders;
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10. A method of monitoring normal transponders in transponder bearing vehicles in a communications zone of a highway toll collection system, comprising the steps of:
causing the system to emit a detection signal if a transmission from a vehicle transponder includes a specific data characteristic;
providing a monitor transponder which emits a sensible signal upon receipt of said detection signal; and
identifying vehicles passing through the communications zone with no sensible signal being emitted from the monitor transponder.
Specification