TDMA network and protocol for reader-transponder communications and method
First Claim
1. A method for providing a TDMA network protocol structure for reader-transponder communications, said method comprising the steps of:
- providing a plurality of time frames within said protocol structure;
dividing each of said time frames into a plurality of defined time slots;
providing a control message time slot within each of said plurality of defined time slots for interrogating a transponder;
providing a plurality of randomly selected time slots within each of said plurality of defined time slots for transmitting an identification message from the transponder in response to being interrogated and for permitting said transponder to gain admission to a TDMA network; and
providing a plurality of assigned time slots within each of said plurality of defined time slots, wherein in response to said identification message from said transponder, said transponder is assigned specific assigned time slots within said plurality of assigned time slots for transmitting data messages during said reader-transponder communications.
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Accused Products
Abstract
A TDMA network for reader-transponder communications including a receiver having an antenna for receiving and transforming radiated energy to a first RF signal and a detector for demodulating and converting the first RF signal to a digital signal. A protocol logic device is provided for decoding the digital signal and for executing a protocol. The protocol comprises a plurality of randomly selected time slots to gain admission to the TDMA network and a plurality of assigned time slots to transmit messages during the reader-transponder communications. In a transponder implementation, an oscillator is provided for converting protocol formatted digital signals from the logic device to a second RF signal. Thereafter, the antenna transforms the second RF signal to radiated energy and transmits the radiated energy. In a preferred embodiment, the TDMA network includes a transmit/receive switch for directing the first and second RF signals along the receive and transmit paths, respectively. A digital memory which communicates with the protocol logic device is provided for storing data unique to a transponder. The protocol also includes a reader control message time slot for interrogating the transponder and an acknowledgment time slot for indicating the reception of a message.
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Citations
11 Claims
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1. A method for providing a TDMA network protocol structure for reader-transponder communications, said method comprising the steps of:
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providing a plurality of time frames within said protocol structure; dividing each of said time frames into a plurality of defined time slots; providing a control message time slot within each of said plurality of defined time slots for interrogating a transponder; providing a plurality of randomly selected time slots within each of said plurality of defined time slots for transmitting an identification message from the transponder in response to being interrogated and for permitting said transponder to gain admission to a TDMA network; and providing a plurality of assigned time slots within each of said plurality of defined time slots, wherein in response to said identification message from said transponder, said transponder is assigned specific assigned time slots within said plurality of assigned time slots for transmitting data messages during said reader-transponder communications. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification