Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may use existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system for tracking vehicle position using a smart phone in the vehicle as an active transponder, which is detected by roadside equipment is disclosed. In an embodiment, the system uses existing RF transceivers on the smart-phone, such as Bluetooth LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further embodiment, the smart phone is alerted by roadside beacons and only then responds with its identification information. Processing can be performed either on the smart phone or by roadside or central office equipment as is the case in prior art active or passive transponder-based tolling systems. Vehicle location detection can be enhanced through the use of directional antenna matrices such as a Butler matrix. The system can be used for automated roadway tolling and monitoring.

Abstract: A system combining readers for RFID transponders and Bluetooth® devices for automated roadway tolling and monitoring is described. Because of the ubiquity of Bluetooth® devices, filtering methods are described to narrow received Bluetooth® signals to a particular monitored traffic lane and to further associate the Bluetooth® signal with a registered RFID toll tag in a vehicle. Signal strength of the Bluetooth® signal at each of a plurality of receiver antennas may be used to identify the location of the Bluetooth® device that emitted the signal.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: Methods, systems, and devices for filler symbols for data bursts are described. A memory device may insert filler symbols into a stream of data symbols. For example, after transmitting a last data symbol of a data burst, a device may insert one or more filler symbols to maintain an active data burst. The device may randomize the transmission of filler symbols within the data burst. In some cases, the device may randomly select filler symbols from a variety of symbol types, therefore randomizing which one of the symbols is transmitted. In some other cases, the device may randomize the representation of filler symbols within an encoding scheme.

Abstract: Methods, systems, and devices for an adjustable periodicity of burst access operations are described. Generally, the described techniques relate to mitigating electromagnetic emissions associated with issuing access commands by adjusting a periodicity according to which the access commands are issued. For example, a first set of one or more commands to perform a first type of access operation may be issued according to a first time delay and a second set of one or more commands to perform the first type of access operation may be issued according to a second time delay, which may be different or the same as the first time delay. The second time delay may be (e.g., randomly) determined based on a value that is selected by a device that issues the commands, the value associated with modifying a periodicity according to which commands to perform the first type of access operation are issued.

Abstract: A system for tracking vehicle position using a smart phone in the vehicle as an active transponder, which is detected by roadside equipment is disclosed. In an embodiment, the system uses existing RF transceivers on the smart-phone, such as Bluetooth LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further embodiment, the smart phone is alerted by roadside beacons and only then responds with its identification information. Processing can be performed either on the smart phone or by roadside or central office equipment as is the case in prior art active or passive transponder-based tolling systems. Vehicle location detection can be enhanced through the use of directional antenna matrices such as a Butler matrix. The system can be used for automated roadway tolling and monitoring.

Abstract: A system combining readers for RFID transponders and Bluetooth® devices for for automated roadway tolling and monitoring is described. Because of the ubiquity of Bluetooth® devices, filtering methods are described to narrow received Bluetooth® signals to a particular monitored traffic lane and to further associate the Bluetooth® signal with a registered RFID toll tag in a vehicle. Signal strength of the Bluetooth® signal at each of a plurality of receiver antennas may be used to identify the location of the Bluetooth® device that emitted the signal.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system for tracking vehicle position using a smart phone in the vehicle as an active transponder, which is detected by roadside equipment is disclosed. In an embodiment, the system uses existing RF transceivers on the smart-phone, such as Bluetooth LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further embodiment, the smart phone is alerted by roadside beacons and only then responds with its identification information. Processing can be performed either on the smart phone or by roadside or central office equipment as is the case in prior art active or passive transponder-based tolling systems. Vehicle location detection can be enhanced through the use of directional antenna matrices such as a Butler matrix. The system can be used for automated roadway tolling and monitoring.

Abstract: A system for tracking vehicle position using a smart phone in the vehicle as an active transponder, which is detected by roadside equipment is disclosed. In an embodiment, the system uses existing RF transceivers on the smart-phone, such as Bluetooth LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further embodiment, the smart phone is alerted by roadside beacons and only then responds with its identification information. Processing can be performed either on the smart phone or by roadside or central office equipment as is the case in prior art active or passive transponder-based tolling systems. Vehicle location detection can be enhanced through the use of directional antenna matrices such as a Butler matrix. The system can be used for automated roadway tolling and monitoring.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system is described for measuring distance between an RFID reader and an RFID backscatter tag, including an adaptive linear combiner, which is a tapped delay line with controllable weights on each tap, and outputs that are summed and subtracted from a reference to produce an error signal. After a sufficient number of cycles, the weight distribution indicates the delay of the received signal with respect to the reference, and by extension determines the distance between the tag and receiver.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system is described for tracking vehicle position using a smart phone or similar device as an active transponder that communicates with roadside equipment. The system may uses existing RF transceivers on the smart-phone, such as Bluetooth® LE or WiFi to periodically transmit an identifying message. Road-based equipment detects and locates the smart phone. In a further aspect, the smart phone is alerted by roadside beacons and responds with identification information. Transaction processing may be performed either on the smart phone or by roadside or back office equipment. The system may be used for automated roadway tolling and monitoring and also for access control. A coded card may be scanned by the smart card to enter identification for access control.

Abstract: A system is described for measuring distance between an RFID reader and an RFID backscatter tag, including an adaptive linear combiner, which is a tapped delay line with controllable weights on each tap, and outputs that are summed and subtracted from a reference to produce an error signal. After a sufficient number of cycles, the weight distribution indicates the delay of the received signal with respect to the reference, and by extension determines the distance between the tag and receiver.

Abstract: The a system for measuring distance between an RFID reader and tag, including an adaptive linear combiner, which is a tapped delay line with controllable weights on each tap, and outputs that are summed and subtracted from a reference to produce an error signal. After a sufficient number of cycles, the weight distribution indicates the delay of the received signal with respect to the reference, and by extension determines the distance between the tag and receiver.

Abstract: The a system for measuring distance between an RFID reader and tag, including an adaptive linear combiner, which is a tapped delay line with controllable weights on each tap, and outputs that are summed and subtracted from a reference to produce an error signal. After a sufficient number of cycles, the weight distribution indicates the delay of the received signal with respect to the reference, and by extension determines the distance between the tag and receiver.