TDMA network and protocol for reader-transponder communications and method
US5425032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1994 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Feb 10, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/2643
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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 t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.