Patent ID: 7864045

Claim:
An inventory management system that is arranged for tracking inventory in a predefined area, the system comprising: a central processing unit that is arranged to process and track inventory in response to communications received from locators over a communication network; a plurality of locators that are each arranged at different locations proximal to the predefined area, wherein each of the plurality of locators is arranged for communicating with the central processing unit over the communication network, and also for communicating with transponders located within the predefined area, wherein a selected one of the plurality of locators is configured to encode a transmission sequence with an identifier associated with a predefined group of transponders, and transmit the encoded transmission sequence in a first wireless broadcast; and wherein each of the plurality of locators is configured to receive one or more reply transmission sequences after transmission of wireless broadcast is initiated, correlate each received reply transmission sequence with a group identified sequence to generate a correlation vector for each received transmission sequence, wherein the group identified sequence is associated with the predefined group of transponders, determine a time of arrival for each corresponding correlation vector, and forward each time of arrival and corresponding correlation vector to the central processing unit for inventory and location tracking; and a transponder that is arranged to receive the wireless transmission sequence, wherein the transponder is positioned within the predefined area, identified with the group of transponders and arranged to: receive and capture information from at least a portion of the wireless broadcast; correlate the captured information with an internally stored reference sequence, wherein the internally stored reference sequence is associated with a designated group; identify a correlation when the received and captured information correlates with the internally stored reference sequence; encode a reply sequence with an identifier associated with the transponder after a correlation is identified; determine a precise time interval based on the previously received locator signal timing parameters for transmitting the encoded reply sequence after the correlation is identified; and transmit the encoded reply sequence in a second wireless broadcast, wherein the transmission of the encoded reply sequence is transmitted at the precisely determined time interval to avoid transmission collisions.