Active RFID :For Critical Uses
(Via Infoworld)The generic term RFID refers to more than just the cheap tags that companies slap onto pallets to comply with retailers' edicts. Several types of RFID systems exist. Wal-Mart requires passive RFID tags. Ephraim Schwartz points out that the "very best" for
enterprise needs may be active RFID tags and the infrastructure that supports them. Passive tags are not powered, so they have a range of just a few feet. A reader must "wake them up," at which point they transmit the little bit of data that they hold. Passive tags also have difficulty sending data through liquids or metal. Active tags, on the other hand, can have a range of as far as 300 feet, are battery-powered, and can either transmit constantly or be activated by an actuator. Both active and passive tags allow data to be captured and put into a database. Add business rules that relate to the tag or groups of tags, and presto! A higher-level application is created. The difference between active and passive is in the kinds of applications the enterprise can build on top of the information that each transmits.
We covered in the post how RFID will play a central role in processes both inside and across enterprises.The sheer volume of traffic generated by a pallet of lemons could be huge. – but business requires that all info be available in realtime using superior filtering mechanisms and smart pattern inference mechanisms.
Active tags shine in high-velocity, chaotic environments, - typically in situations 2,000 gate moves per day at the height of the buying season, passive tags would be useless; each truck would have to stop and get scanned. With active tags, however, the trucks roll in and out. And not only does the manager know when each container has arrived, but even in a yard hundreds of acres large, he knows exactly where everything is at all times. Active tags can also be used for security. A laptop, for example, might be tagged and associated with an employee pass card. If the two don't match as the employee goes through an exit, an alert can be triggered. A passive tag won't work in this case because there is no way of ensuring that the tag will be read as it passes the reader. Business needs to assess usage of active tags for long term benefits. Active tags may be more expensive, but they open up a whole new world of wireless possibilities