FID uses radio waves to automatically identify or track personnel and materials. It has replaced the bar code in many applications where the bar-code-required line of sight is unavailable. A unique serial number is stored on a microchip that is attached to an antenna. This transponder, or ID tag, can either transmit to or be read from the RF reader.
The reader, which also contains an antenna, sends radio waves that the transponder then reads. There are three types of tags: active, passive and semi-passive. An active RFID tag includes a battery that powers the tag's internal circuits, allowing it to send signals to the reader. A passive RFID tag uses the electromagnetic field created by the reader to power its own circuits. The microchip then modulates the radio waves that the tag sends back to the reader, and the reader converts the data for use within the computer. A semi-passive tag uses a battery to run the tag's circuitry, but sends the information using only the reader's power.
Improvements in technology and changes in the national security outlook have made RFID solutions more attractive than ever to a number of markets. Applications in access control and integrated personnel tracking, transportation security, supply chain management and homeland security in particular have increased significantly over recent years.
Access Control and Personnel Tracking
Many access control companies offer RFID-based access. Some companies also now offer RFID access solutions that feature tracking options. Axcess International Inc. has developed a method to track personnel and assets that are critical to a company's security. The system, known as the Axcess ActiveTag System, "operates with personnel wearing Axcess active tags uniquely identifying each person, allowing the access control system to quickly authorize or deny access or detect the presence of unauthorized personnel in the area," said Allan Griebenow, CEO and president of Axcess.
Systems like this track personnel moving from one location to another and can deny access if they are not authorized to enter. Such systems can also identify and track who is in the building at all times, thus providing an accurate account of who did or did not get out of a building in an emergency. This is all accomplished with no buttons to push or cards to swipe. All cards can be read at any given time without having to send personnel through a choke point for reading.
RFID systems designed for use with large vehicles are a great asset to inventory and the transportation industry. Security personnel can equip rail cars with RFID tags to allow tracking by station and yards along the route. Cars can be rerouted at any time and shipments moved to another destination without any manual input. Some systems offer wireless sensing tags that can monitor temperature, humidity, pressure, radiation and even ammonia gases. With this type of technology, the temperature inside refrigerator cars can be tracked to ensure the integrity of their contents.
Companies like AWID and Nedap offer technology that tracks vehicle access to parking areas through tags on the vehicles themselves. Such systems may be enhanced by linking the vehicle to the driver, the truck to the trailer, and/or the trailer to its authorized cargo, in order to ensure that not only is the vehicle authorized to enter or exit the area, but the correct cargo is leaving with the correct truck cab, and the driver is authorized to take the vehicle out. This system is a viable method to prevent asset thefts.
The Georgia Institute of Technology's Parking and Transportation Department presently uses a vehicle location module on a portion of its campus transportation fleet. The department plans to expand the system to all buses and trolleys in the current fiscal year. The VLMs transmit the coordinates of each vehicle's location every 15 to 25 seconds. Their tracking system is integrated with a geographic information system, which identifies the location of the vehicle at any given time and estimates the arrival time of the vehicle at each passenger stop. Not only does the system determine time and route management, coupled with rider ship counts, it can determine the proper support to the campus of all vehicles in the inventory.