6594results about "Subscribers indirect connection" patented technology

A method is described of calculating and verifying the integrity of data in a data communication system. The system comprises a base station and one or more remote stations, such as in an RFID system. The method includes transmitting a select instruction from the base station to the one or more remote stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; transmitting from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.

A radio frequency beacon device for use with a backscatter interrogator includes a processor; a receiver coupled to the processor; a backscatter modulator coupled to the processor; and an active transmitter coupled to the processor, the active transmitter being configured to transmit an RF signal, in response to a trigger signal, regardless of whether the interrogator is providing a carrier wave for backscatter modulation by the backscatter modulator. Other methods and apparatus are provided.

In a protocol for preserving the privacy of communications between a RFID reader and a RFID tag, two distinct actions are taken. First, the reader and the tag must be mutually authenticated as being authorized participants in the communications. After that process is successfully completed, the authenticity of each authorized participant must be validated prior to each subsequent communication between reader and tag.

An encoded information reading (EIR) terminal can comprise a microprocessor electrically coupled to a system / data bus, a memory communicatively coupled to the microprocessor, an EIR device, a multi-band antenna, and a wireless communication interface. The EIR device can be provided by a bar code reading device, an RFID reading device, or a card reading device. The EIR device can be configured to output raw message data containing an encoded message and / or output decoded message data corresponding to an encoded message. The wireless communication interface can comprise a radio frequency (RF) front end electrically coupled to the multi-band antenna. The RF front end can comprise a micro-electromechanical (MEMS) filter array including one or more band-pass filter. Each band-pass filter of the MEMS filter array can be electrically coupled to a bias voltage source or an oscillating signal source. The RF front end can be electrically coupled to an analog-to-digital (A / D) converter and / or to a digital-to-analog (D / A) converter. The wireless communication interface can be configured to transmit radio signals in two or more frequency regulatory domains and / or receive radio signals in two or more frequency regulatory domains. The multi-band antenna can in one embodiment be provided by a meta-material antenna.