Wi-Fi Real Time Location Systems (RTLS): a possible substitute for RFID?
Given that many companies already have Wi-Fi networks, Wi-Fi Real Time Location Systems (RTLS) may be a cheaper alternative to some more expensive radio frequency identification (RFID) technology applications, according to one analyst.
The analyst cited is Stan Schatt, vice-president and research director of ABI Research.
By using Wi-Fi RTLS, companies can leverage their existing Wi-Fi network, although they might have to add access points to provide complete coverage. The advantage is that RFID readers are expensive, and Wi-Fi RTLS is an open standard so that the company needn't invest in proprietary equipment. With Wi-Fi RTLS, you also have the bonus of being able to integrate this location system in to an existing Wi-Fi network. You avoid having to install and manage a separate network.
The downside is that Wi-Fi RTLS doesn't have the accuracy of RFID. This article gives the example of tracking palettes on a loading dock. Wi-Fi RTLS wouldn't work well with tracking individual packages on palettes, since its accuracy is limited to within one foot.
Here's another caveat:
Another imperfect application of Wi-Fi RTLS is in wide-open spaces that present a lot of interference like the outdoors or in large warehouses in which the signal would bounce of walls and other objects, said Schatt.
However, you don't have this problem with 802.11n, which is the first 802.11 standard to support multiple-input multiple-output (MIMO). Inf fact, 802.11n requires MIMO to work optimally. What MIMO does is to allow multiple antennas at the transmitter and receiver so that the multiple signals created by bouncing off different objects can be collected and use to transmit data while increasing throughput and link range without additional bandwidth or transmit power.