RFID

Healthcare Informatics has a guest article by Richard Barnwell of PanGo
Networks
on RFID in hospitals. The story includes a nice review of some
of the high level benefits RFID can bring to a hospital. Assurances are
made that the technology has matured “beyond a technology for early
adopters into one of the mainstream.” There was one bit that I took
exception to:

Wireless asset-tracking capabilities traditionally have been the domain
of single-purpose real-time tracking systems requiring their own
dedicated, proprietary network infrastructure. The intensive hardware
deployment required make them costly to purchase, install, implement
and maintain.

In contrast, Wi-Fi-based EAV solutions leverage existing Wi-Fi
infrastructures, obviating specialized radio receivers, access points,
antennas and wiring. By using software-only location architectures,
newer EAV [enterprise asset visibility] solutions dramatically lower the total cost of ownership and
open up new possibilities through combined services.

While I'm sure that there are situations where the above is true, it is
far from a sure thing, and here's why. There is a direct relationship
between location resolution and the density of receivers that determine
the location of tagged assets. Locating patients and assets to
generalized zones takes fewer receivers than locating something to a
particular room or bed in a semiprivate room.

Every wireless deployment, whether 802.11 WLAN for data, or other
technologies dedicated to indoor positioning, requires a site survey.
This survey measures RF (or infrared) performance within the actual
space and ensures the proper placement of receivers for the desired
level of accuracy. Site surveys done to place 802.11 access points
(APs) for data are different from surveys done for indoor positioning.
Frequently additional APs are required when adding indoor positioning
capabilities to a WLAN — sometimes a lot more. Depending on the cost
of APs (both for 802.11 and alternative technologies), this can more
than erase the benefit of leveraging existing 802.11 infrastructure.

Purpose specific RFID systems typically have lower cost receivers and
tags because they are not burdened by the additional requirements of a
WLAN; they are simpler and less complex. As a result, vendor selection
should be based on needs and requirements rather than the base
technology on which a particular solution is based.

The bottom line is that determining the RFID technology that's best for
you depends on your unique situation. There are no slam dunks.