"The system employs a transmission method called "tag talks only" (TTO), as opposed to "reader talks first" (RTF) and "tag talks first" (TTF) methods. Utilized by RFID systems based on the EPCglobal or ISO 18000-6 standards, RTF has interrogators (readers) initiating communication between a tag and reader in a set of sequences. The interrogator sends energy to the tags, but the tags sit idle until the reader requests them to respond. The reader can identify a specfic tag and request data from it by using a complex sequence of commands to select a particular subset of tags, singulating one tag from this subset using an anticollision algorithm, and reading the required data it contains."