Real-Time Location Systems: Taking Active RFID To The Next Level By Tuomo Rutanen, Ekahau

Real-time location systems (RTLS) are often lumped into the active RFID category, and in a very basic sense, the classification does fit — both RTLS and active RFID systems use battery-powered tags to track the movement of assets.

However, there are significant differences between the two technologies, the most obvious being that active RFID is typically used only for identification, as the name RFID implies. Rather than knowing the precise location of objects, active RFID usually only knows that the objects are within the footprint of a sensor and are somewhere in a defined space. RTLS, on the other hand, can automatically monitor the location of an object at any given moment anywhere in a defined space, whether or not the object has moved.

Building on this capability, Wi-Fi RTLS leverages the strengths of an existing 802.11 network as its backbone to provide RTLS services. The wide deployment of Wi-Fi networks could ultimately change the way we think about RTLS, which in turn may redefine what we mean when we say active RFID.

In fact, now that RFID users are beginning to understand the difference between active RFID and RTLS, some very interesting applications are beginning to emerge. This article will provide some background information on RTLS and will detail ways in which Wi-Fi RTLS can be used to do everything from tracking objects across international boundaries to locating items on crowded shelves.