Abstract: Embodiments of a method for clock synchronization in a radio frequency identification (RFID) equipped device, an RFID equipped device, and a hand-held communications device are described. In one embodiment, a method for clock synchronization in an RFID equipped device involves measuring a difference between a field clock frequency generated from an external clock and an internal clock frequency generated from an internal clock and generating outgoing bits in the RFID equipped device in response to the measured difference. Generating the outgoing bits involves adjusting the bit length of at least one of the outgoing bits in response to the measured difference. Other embodiments are also described.

Abstract: A method of wireless communication, with a circuit that includes a radio frequency identification (RFID) reader, can be carried out using a circuit that is configured and arranged to communicate with RFID cards that use load modulation of an RF carrier provided by the RFID reader. A presence of the radio frequency (RF) carrier is detected on an antenna. A local clock signal is generated. A difference between the local clock signal and the RF carrier is detected. In response to the detected difference, the frequency of the local clock signal is modified to reduce the detected difference. Load modulation of the RF carrier is mimicked by modulating the local clock signal to encode data; and driving the antenna with the modulated local clock signal.

Abstract: A circuit for delivering power to a load from a wireless power supply comprises an inductor coil for placing in the electromagnetic field of an inductor coil of a supply and a switchable capacitor bank with capacitors switchable at least between a series and a parallel configuration. The voltage across the capacitor bank is used as a feedback control parameter for controlling the capacitor bank switching. A voltage regulator is used to supply the load with a constant voltage power supply derived from the capacitor bank output.

Abstract: In a method of inventorying data carriers by means of a communication station, whereby the communication station and each data carrier are brought into communicative connection, and each data carrier brought into communicative connection with the communication station is capable of generating a response signal that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal with the use of a transmission start moment that can be selected from a plurality of transmission start moments, each data carrier tests whether another data carrier is already giving its response signal. Each data carrier subsequently discontinues the generation or delivery of its response signal if another data carrier is already providing its response signal.

Abstract: Data carriers for inventorying by means of a communication station, whereby the communication station and each data carrier are brought into communicative connection, and each data carrier brought into communicative connection with the communication station is configured to generate a response signal that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal with the use of a transmission start moment that can be selected from a plurality of transmission start moments, each data carrier tests whether another data carrier is already giving its response signal. Each data carrier is configured to discontinue the generation or delivery of its response signal if another data carrier is already providing its response signal.

Abstract: In a method of inventorying data carriers by means of a communication station, whereby the communication station and each data carrier are brought into communicative connection, and each data carrier brought into communicative connection with the communication station is capable of generating a response signal that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal with the use of a transmission start moment that can be selected from a plurality of transmission start moments, each data carrier tests whether another data carrier is already giving its response signal. Each data carrier subsequently discontinues the generation or delivery of its response signal if another data carrier is already providing its response signal.

Abstract: An RFID communication system comprises an NFC device (11) and a smart card (2) with contactless card functionality, wherein the NFC device (11) and the smart card (2) are couplable to each other via a protocol converter (7), wherein the NFC device (11) is coupled to an antenna (3) to receive electromagnetic signals (ES) from an RFID reader/writer and to transmit response signals (RS) to the RFID reader/writer by modulating received electromagnetic signals (ES). The electromagnetic signals (ES) contain first and second characteristic components (FE, RE) which define the begin and the end of a predefined signal pattern (PA), wherein the second characteristic component triggers a predefined response delay time (FDT) at the expiration of which the RFID communication system has to respond to the RFID reader/writer. A device (12) for compensating signal delays is provided that comprises signal pattern shortening means (13).

Abstract: A method of inventorying data carriers (2) by means of a communication station, whereby the communication station and each data carrier (2) are brought into communicative connection, and each data carrier (2) brought into communicative connection with the communication station is capable of generating a response signal (IDS) that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal (IDS) with the use of a transmission start moment that can be selected from a plurality of transmission start moments (t5, t6), each data carrier tests whether another data carrier (2) is already giving its response signal (IDS). Each data carrier (2) subsequently discontinues the generation or delivery of its response signal (IDS) if another data carrier (2) is already providing its response signal (IDS).

Abstract: Transponder (180) having stored a fixed identification number, which expands said identification number with a random number, encrypts said expanded number with a key, and sends it to a reader (160) on its request. Reader (160), which on request receives an encrypted number from a transponder (180), decrypts a received encrypted number with a key, which was also used by the transponder (180), and extracts a fixed identification number associated with the transponder (180).

Abstract: Reader (420) for determining the validity of a connection to a transponder (440), designed to measure a response time of a transponder (440) and to authenticate the transponder (440) in two separate steps. Transponder (440) for determining the validity of a connection to a reader (420), wherein the transponder (440) is designed to provide information for response time measurement to said reader (420) and to provide information for authentication to said reader (420) in two separate steps, wherein at least a part of data used for the authentication is included in a communication message transmitted between the reader (420) and the transponder (440) during the measuring of the response time.

Abstract: Transponder (104), comprising a storage unit (106) having stored a number of different applications, a processing unit (108) which, on request of a reader (102), is adapted to generate a response interpretable using an encryption scheme known by both the transponder (104) and the reader (102) so that the reader (102) is capable of determining whether an application is supported by the transponder (104) by analyzing the response using the encryption scheme, and a transmission unit (110) adapted to send the response to said reader (102).

Abstract: Method for exchanging data between an NFC device (10) and a transceiver device (20) via a single communication channel (30), comprising the steps:—extracting a clock for the data exchange on the communication channel (30) from an external RF field (50); and—coding of the data via symbols, wherein the symbols comprise status information relating to simultaneous accesses of contactless card functionalities (21, 22, 23) on the transceiver (20) to the single communication channel (30).

Abstract: An RFID communication system comprises an NFC device (11) and a smart card (2) with contactless card functionality, wherein the NFC device (11) and the smart card (2) are couplable to each other via a protocol converter (7), wherein the NFC device (11) is coupled to an antenna (3) to receive electromagnetic signals (ES) from an RFID reader/writer and to transmit response signals (RS) to the RFID reader/writer by modulating received electromagnetic signals (ES). The electromagnetic signals (ES) contain first and second characteristic components (FE, RE) which define the begin and the end of a predefined signal pattern (PA), wherein the second characteristic component triggers a predefined response delay time (FDT) at the expiration of which the RFID communication system has to respond to the RFID reader/writer. A device (12) for compensating signal delays is provided that comprises signal pattern shortening means (13).

Abstract: A method and system for secure RFID system communication is provided. The RFID system comprises an RFID reader (101) communicating with an RFID tag (102). The RFID reader (101) sends (116) to the RFID tag (102) a request to write. The RFID tag (102) generates random data (P), and sends (122) the random data (P) to the RFID reader (101). The RFID system encrypts information (M2) by using the random data (P), and the RFID reader (101) sends (124) the encrypted information (E) to the RFID tag (102) which decrypts the information (E) by using the random data (P). Finally the RFID tag (102) stores (126) the decrypted information (M2) on a memory (103) of the RFID tag (102).

Abstract: In a method of releasing communication between at least two communication devices (4, 5, 6, 7, 8), a data carrier (36), that is able to be read from in a non-contacting manner and that contains an authorization code (AUC), is brought into the vicinity of communication devices (4, 5, 8) that are to be released, and the authorization code (AUC) is read out in a non-contacting manner by a reading device (21, 22, 25) contained in the relevant communication device (4, 5, 8) and is fed by the reading device (21, 22, 25) to a releasing device (40, 41, 44) that, after analyzing the authorization code (AUC), is responsible for releasing communication between the communication devices (4, 5, 8) to be released.

Abstract: In a communication arrangement (1) provided for transmitting data (DA) to a transponder (2) which arrangement includes a data source (5) for delivering data (DA) and includes a carrier signal generator (6) for generating a carrier signal (CS) and includes modulation means (7) to which can be applied the data (DA) and the carrier signal (CS) and which modulation means are provided for modulating a carrier signal (CS) in accordance with the data (DA) and for delivering a modulated carrier signal (CSM) to transmitting means (8) having an input resistance (9), the modulation means (7) have a changeable output resistance (10) which forms a resistance network together with the input resistance (9) of the transmitting means (8), and resistance change means (25) for changing the output resistance (10) in accordance with the data (DA).

Abstract: A method of inventorying data carriers (2) by means of a communication station, whereby the communication station and each data carrier (2) are brought into communicative connection, and each data carrier (2) brought into communicative connection with the communication station is capable of generating a response signal (IDS) that renders possible an inventorying of the data carrier and is capable of delivering a generated response signal (IDS) with the use of a transmission start moment that can be selected from a plurality of transmission start moments (t5, t6), each data carrier tests whether another data carrier (2) is already giving its response signal (IDS). Each data carrier (2) subsequently discontinues the generation or delivery of its response signal (IDS) if another data carrier (2) is already providing its response signal (IDS).

Abstract: In a method of releasing communication between at least two communication devices (4, 5, 6, 7, 8), a data carrier (36), that is able to be read from in a non-contacting manner and that contains an authorization code (AUC), is brought into the vicinity of communication devices (4, 5, 8) that are to be released, and the authorization code (AUC) is read out in a non-contacting manner by a reading device (21, 22, 25) contained in the relevant communication device (4, 5, 8) and is fed by the reading device (21, 22, 25) to a releasing device (40, 41, 44) that, after analyzing the authorization code (AUC), is responsible for releasing communication between the communication devices (4, 5, 8) to be released.

Abstract: A data carrier that communicates confidential data is configured to mask process-dependent power consumption by using power stored in an internal capacitor. The capacitor is initially charged to the voltage of an external power source, and then decoupled from the external power source. The capacitor provides power to an internal processor, and consequently discharges gradually. At the end of a given time interval, the capacitor is discharged to a fixed voltage, then charged to the supply voltage. In this manner the power consumed by charging of the capacitor is decoupled from the power consumed by the processor. If the capacitor drops below a threshold voltage before processing is completed, the processor is halted. To optimize the available processing time, the time interval before discharging the capacitor to the fixed voltage is dynamically adjusted to reduce the time that the processor is halted.

Abstract: In a data carrier (1) that, using signals (S) occurring at transmission means (3), is arranged to make available power for supplying parts of its circuit (2) with power, data processing means (16) are provided for processing data (CD, MD, DD, RD) in at least two different modes of processing, the power made available being dependent on the mode of processing being performed at the time, and also provided are influencing means (18) that are arranged to influence the data processing means (16) in respect of the latter's mode of processing in the light of the power available.