US Patent 6959862 Inventory control and identification method

An inventory control and identification apparatus uses a storage space with a plurality of inventory items. Identification labels are positioned in physical correspondence with the inventory items. Each of the identification labels provides a transceiver. A coordinate communications network of further transceivers is set in a fixed position relative to the storage space and is enabled for wireless communication with the identification labels. A data processor is enabled for wireless communication with the coordinate network and the identification labels so as to receive data from the labels and the network. Inventory items have RF ID tags. Interrogation by the labels enables the tags to emit codes identifying the presence and location of the inventory to the labels. Triangulation of signals transmitted by the labels enables location of the labels in three-space.