Last fall as one of the top inventions for 2008, Time Magazine listed "The Internet of Things" -- described as a network of sensors that can talk to one another. While this talking amongst things will lead to a host of new applications, at Entigral we are interesting in tracking stuff.
Passive RFID can be viewed as the first step toward The Internet of Things: the identification of each thing. Entigral thinks of this as the serialization of entities (ergo, our name). Once an entity is identified we can now track it. Passive RFID tags are cheap but have a range of about ten feet, which puts limits on our internet of things! Plus, without an external radio field a passive tag is nothing more than an inert sand speck. How can we do more?
Active RFID is the next step toward The Internet of Things. Active tags are powered by a battery, or by harvesting power from sources like vibration, induction, or solar energy. Active tags can continuously monitor and communicate properties of the objects to which they are attached, so they are ideal not only for tracking stuff but also for noting physical conditions like light levels, temperature, movement, or even that someone pushed a button. Furthermore, communication can be two-way, so an active tag can control the object to which it is attached.
A new generation of active tags (based on ZigBee for example) can form a local network mesh to pass along information even if the internet is unavailable. Riding advancements in memory and chip miniaturization, new active tags can do more and live for years on coin cell batteries out on the network edge monitoring, controlling and communicating. We can expect the same adoption curve with active RFID that we saw with passive -- standardization will drive volume up and costs down.
In conclusion, existing passive RFID technologies make The Internet of Things a reality today for asset tracking applications. New active RFID technologies let us track assets that have been infeasible to track with passive RFID because of reader cost or physical limitations.
