RFID uses wireless links to uniquely identify objects using dedicated short-range communications. When RFID tag enters the read zone of a reader, the data and address on the tag is read and can be sent to a server for location tracking.Passive No batteries, tag’s antenna captures radio power from a reader, stores in a capacitor, powers circuits and sends signal(answer) on a different frequency (Walmart)Active Most sophisticated, has batteries, data storage, larger range, sophisticated functions, (encryption) Battery Assisted Passive(BAP)Small battery, activated only in the presence of the readerRFID readers can be fixed or mobile. Multi-dimentional grid of RFID readers are used to cover the whole area (warehouse). Maximum distance between two neighboring readers canbe based on the range of readers and location accuracy required Cost, accuracy, reliability.PANs – Bluetooth designed for short range wireless communications among printers, phones etc. designed to replace wiring used among devices so it is a low power wireless standard for connecting devices.