TDMA network and protocol for reader-transponder communications and method

Abstract

Abstract A TDMA network (100) for reader-transponder communications including a receiver (132) having an antenna (116) for receiving and transforming radiated energy to a first RF signal and a detector (106) for demodulating and converting the first RF signal to a digital signal. A protocol logic device (110) is provided for decoding the digital signal and for executing a protocol. The protocol comprises a plurality of randomly selected time slots (152) to gain admission to the TDMA network (100) and a plurality of assigned time slots (154) to transmit messages (164) during the reader-transponder communications. In a transponder (114) implementation, an oscillator (108) is provided for converting protocol formatted digital signals from the logic device (110) to a second RF signal. Thereafter, the antenna (116) transforms the second RF signal to radiated energy and transmits the radiated energy. In a preferred embodiment, the TDMA network (100) includes a transmit/receive switch (130) for directing the first and second RF signals along the receive and transmit paths, respectively. A digital memory (138) which communicates with the protocol logic device (110) is provided for storing data unique to a transponder (114). The protocol also includes a reader control message time slot (156) for interrogating the transponder (114) and an acknowledgment time slot (158) for indicating the reception of a message (164).

Inventors

• 👤 Peter D. Shloss
• 👤 Michael S. Friedman
• 👤 Dale R. Feikema

Bibliographic Details