摘要:
An RF power oscillator for contactless card antennas shapes a carrier signal at the operating frequency utilizing a delay circuit having a number of taps for delaying the carrier signal by different lengths of time. The delayed signals are input into a buffer and output through resistors to a node coupled to the antenna. The resulting waveform for a square wave input signal, and equal-length delay taps, is a trapezoidal wave output. Any input wave form can be shaped in a variety of ways depending upon the combinations of delay taps used. Since the buffer drivers for each delayed wave switch state at slightly different times, the amplitude and bandwidth of emitted electromagnetic interference (EMI) is reduced for the transmission circuit.
摘要:
An RF power oscillator for contactless card antennas shapes a carrier signal at the operating frequency utilizing a delay circuit having a number of taps for delaying the carrier signal by different lengths of time. The delayed signals are input into a buffer and output through resistors to a node coupled to the antenna. The resulting waveform for a square wave input signal, and equal-length delay taps, is a trapezoidal wave output. Any input wave form can be shaped in a variety of ways depending upon the combinations of delay taps used. Since the buffer drivers for each delayed wave switch state at slightly different times, the amplitude and bandwidth of emitted electromagnetic interference (EMI) is reduced for the transmission circuit.
摘要:
Techniques are provided herein that enable local fare processing for access control points (entry gates, turnstiles, etc.) in a transit or similar system that can detect fraudulent activity far more quickly than fare processing systems using traditional blacklists or whitelists—and even detecting fraudulent activity at a first occurrence. Embodiments take advantage of the relatively high communication speed and memory capacity of modern transit systems to generate a list of all applicable cards with usage data such as the time of last use, value, or other “one directional data,” provide it to each access control point in the system. The access control point, upon reading fare media, can then compare the data on the fare media to data on the list to determine whether fraud may be taking place. The access control point may then determine whether to allow access, flag the fare media, and/or take another action.
摘要:
Techniques for protecting communication between a card reader and a contactless smartcard are disclosed. In one embodiment, a protocol transmitter includes a transmit circuit and a processor. The transmit circuit is configured to generate a blocking signal having a frequency used by the card reader to communicate with the contactless smartcard. The processor is coupled to the transmit circuit and configured to modulate the blocking signal according to a communication protocol of the contactless smartcard. A first antenna of the protocol transmitter is disposed a predetermined distance from the card reader and is coupled to the transmit circuit to radiate the blocking signal. Optionally, the processor modulates the blocking signal so as to simulate a data exchange between the card reader and the contactless smartcard.
摘要:
Embodiments of the invention integrate a contactless media reader with sensors to detect that an object is within the contactless media reader operating field and optionally detect the position, orientation and speed of the object as it approaches the contactless media reader. The object can be, for example, a contactless fare media such as a contactless smartcard, a personal processing device such as a smart phone, personal computer, tablet computer or the like, or the user's hand, one or more fingers, or both. Embodiments may use one or more distance/position sensors to determine the position of the contactless fare media relative to the contactless media reader. Accordingly, embodiments of the present invention enhance contactless media reader performance by adding user interaction capabilities and providing feedback to the contactless fare media user.
摘要:
Systems and methods for RFID fare collection for improving passenger throughput and security in transit systems. RFID tags identify passengers at a distance and allow a hands-free experience for transit users. The system includes gate cabinets and/or other entry points that define a passageway and separate a non-restricted access area from a restricted access area, at least one RFID transmitter positioned on the entry points, at least one RFID receiver positioned on the entry points, and a processor coupled with the RFID receiver. The system detects the presence of the RFID tag within the passageway and detects information linking to the account balance of the user. The system determines whether transit users are entering or exiting the restricted access area based on analysis of the wireless signals received by the RFID receivers, and provides an alarm signal when a transit user is not permitted to access the restricted access area.
摘要:
Systems and techniques are presented for determining the position of a mobile device. The mobile device receives two beacon packets transmitted at varying power levels by a first beacon and determines received signal strength (RSS) levels for the beacon packets. A maximum distance and a minimum distance are determined based on the power levels that the packets were transmitted at and the RSS levels that the packets were received at. An area around the first beacon is determined based on the distance range. The mobile device receives two additional beacon packets transmitted at varying power levels by a second beacon and determines RSS levels for the beacon packets. A distance range between the mobile device and the second beacon is determined and an area around the second beacon is determined based on the distance range. The area of overlap between the beacons is where the mobile device is positioned.
摘要:
Techniques for protecting communication between a card reader and a contactless smartcard are disclosed. In one embodiment, a protocol transmitter includes a transmit circuit and a processor. The transmit circuit is configured to generate a blocking signal having a frequency used by the card reader to communicate with the contactless smartcard. The processor is coupled to the transmit circuit and configured to modulate the blocking signal according to a communication protocol of the contactless smartcard. A first antenna of the protocol transmitter is disposed a predetermined distance from the card reader and is coupled to the transmit circuit to radiate the blocking signal. Optionally, the processor modulates the blocking signal so as to simulate a data exchange between the card reader and the contactless smartcard.
摘要:
A Universal Ticket Transport (UTT) 10, 150 may be configured to read from and write to many types of magnetically encoded tickets 20 currently used in fare collection systems. The UTT 10, 150 includes a mechanical insertion interface and automated movement along a transport path 18 for tickets 20 of varying thicknesses that are presented at a range of different angles 40, 42 into and exiting from the UTT 10, 150. The UTT 10, 150 includes a mechanical assembly 156, 158 which may be rotated, and the belts 22, 24, 152, 154 and rollers 30, 32, 34, 36 reconfigured, to accommodate tickets 20 having top-face or bottom face magnetic stripes. The belt subassemblies A, C and the magnetic head subassembly B are configurable across a width W of the UTT 10, 150 to process tickets 20 having magnetic stripes which are offset from a center line 86. The UTT 10,150 includes a control processor 200 having analog to digital interfaces 216 and control logic 202, 204 for operating the transport mechanisms 212 locally and communicating data through a serial interface 220 to a host system 222.