RFID refers to the use of radio frequencies that helps in capturing information stored on a tag. While some tags are active, some are passive. Passive RFID tags do not have an internal power source and they receive energy from radio frequency that is sent out from a module. This has been useful for traditional access control systems and the badge is placed near a receiver for identification purpose.
Active RFID tags comprise of a battery that continuously transmits all information with radio frequency. The tags are ideal for tracking assets and personnel as these active RFID tag can easily send out stronger signal without facing any interruption from human body or metal surfaces. Active badges can initiate communication with the help of a receiver. For example, an employee can push the panic button on the badge in order to send out an SOS. The signals that are sent out by RFID tags comprise of information, which is associated with a visitor or a person in the system. The receiver can be easily adjusted for picking up the tag transmissions that is in a specific area. The signals transmit through floors, walls and ceilings and hence modules do not need line of sight in order to locate personnel.