Patent ID: 7830262

Claim:
An operational processing block for a Radio Frequency Identification (RFID) reader to inventory a population of RFID tags, comprising: a component for: causing to be established a first set of values for communication parameters; causing to be transmitted first inventorying commands for inventorying the RFID tags, and receiving, responsive to the first inventorying commands, first replies that are backscattered from a first subgroup of RFID tags in the population, at least one of the first inventorying commands and the first replies using communication parameters having the first set of values; then causing to be established a second set of values for the communication parameters, different from the first set of values; and causing to be transmitted second inventorying commands that are suitable for continuing inventorying those of the RFID tags in the population that are not in the first subgroup, but not suitable for continuing inventorying at least one of those that is in the first subgroup, and receiving, responsive to the second inventorying commands, second replies that are backscattered from a second subgroup of RFID tags in the population that does not include the first subgroup, at least one of the second inventorying commands and the second replies using communication parameters having the second set of values, in which at least one tag of the first subgroup and at least one tag of the second subgroup are powered from both the first and the second inventorying commands, and remain continuously powered during a transition between the first and the second inventorying commands.