Method and system for communicating with and tracking RFID transponders
US7253717B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2000 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Feb 23, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/2417
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An RFID system and method for communicating between a host computer, one or more interrogators connected to the host computer, and a large body of transponders distributed within an area covered by the interrogators. Each transponder originally has a common identification code, and upon initialization by the host computer internally generates a unique identification code based upon an internally generated random number. The host, through the interrogators, reads each of the identification codes associated with each transponder by iteratively transmitting a read identification code command along with a controlled variable. Each transponder compares the received controlled variable to an internally generated random number, and selectively transmits its identification code based upon the outcome of this comparison. After the completion of each read identification code iteration, the host adjusts the controlled variable based upon the responses received in the previous iteration. Preferably, communications between the interrogators and the transponders are DSSS signals in TDMA format, and the transponders use the random number generator to assign a time slot for transmission of their r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.