Ekahau’s Positioning Engine 2.0
provides a software-based system that enables location-based applications for
wireless LANs. The complete positioning system includes the Ekahau Client, Ekahau
Positioning Engine and Ekahau Manager. Each user device that the system tracks,
such as a laptop or PDA, must be running the client software. The Ekahau Positioning
Engine is Java-based server software that calculates the user device locations,
and the Ekahau Manager is a platform for creating positioning models, tracking
devices, and analyzing positioning accuracy.
Pros:
- Works with most wireless LAN access points.
- Sufficient accuracy for many indoor applications.
Cons:
- Somewhat difficult to setup and calibrate (high learning curve).
- Each user device that the system tracks requires specialize software.
Some points to consider
A significant advantage of Ekahau’s positioning system is that it doesn’t require
the installation of specialized access points. You can use the access points
already installed within your facility. In fact, Ekahau’s Positioning Engine
can operate over just about any type of wireless LAN, such as 802.11 or HiperLAN.
The accuracy of the positioning system seems adequate for most indoor applications.
While testing the system with four access points in a 2,000 square foot office,
the system had an average accuracy of 1.9 meters (about 6 feet). At best, the
accuracy was around 0.6 meters (about 1.5 feet). While ou certainly wouldn’t
want to use the system for positioning robots drilling holes into parts with
this level of accuracy, but it will satisfy many applications. For example,
organizations can use it to track the location of forklifts in a warehouse,
doctors within a hospital, or other important resources.
It’s possible to increase the accuracy of the positioning system by adding
a greater number of access points. Ekahau claims that the system will provide
up to one meter average accuracy, but that requires the clients to be within
range of more than four access points at any given time. Ten access points would
provide superb accuracy, but it’s unlikely that users will be within range of
more than four or five access points at a time as they roam throughout the facility.
The process for setting up the Ekahau’s positioning system is fairly straightforward,
but be ready for a learning curve when installing it for the first time. In
addition, the setup process can consume a great deal of time depending on the
accuracy levels you require. This is not a plug and play solution.
You begin the setup process by creating a positioning model that includes a
floor plan that you include as an image file with overlaid tracking rails on
top for during the calibration process. With a user device equipped with the
Ekahau Client, you’ll then walk through the facility and click a map to record
sample points every ten feet or so. At each sample point, you rotate 360 degrees
to capture access point signals from all directions. This can be somewhat tedious
and time consuming over a large facility
After calibrating the system, you initiate tracking from within the Ekahau
Manager. An onscreen display shows each tracked user’s position on the floor
plan in real-time. Despite learning curve to get to this point, it was pretty
impressive to watch the users move across the floor plan.
Before using the system for a specific application, you can view the accuracy
readout as a gauge to determine whether you should add or move some access points
to optimize accuracy. Be sure the accuracy is acceptable before deploying the
actual positioning applications.
Because you must install the Ekahau Client on each of the user devices that
the system tracks, the resulting location applications best fit a private network
where a company has control over all client devices. Of course, the implementation
of a tracking mechanism without requiring specialized software on the user device
would be difficult, and privacy issues would surface because you could track
users without their knowledge.
Some final thoughts
The integration of positioning within wireless LAN applications opens the door
to exciting and beneficial applications. The Ekahau system is certainly one
worth using as the basis for these location-based solutions. Before attempting
a large deployment, however, become familiar with the system by experimenting
with a small-scale prototype to gain a solid understanding of the setup procedures
and elements that impact accuracy.
You can do this with the free 30-day evaluation version of the system. To try
it, complete an online application form. The
price for a full system license for tracking 2 clients is $595. The Ekahau system
can track hundreds of devices, but Ekahau doesn’t advertise prices for broader
licenses. You need to contact their sales department for pricing beyond just
two clients.
For more information on positioning systems for wireless LANs, refer to the
tutorial "Deploying Indoor
WLAN Positioning Systems."
Jim Geier provides independent consulting services to companies developing
and deploying wireless network solutions. He is the author of the book, Wireless
LANs and offers computer-based
training (CBT) courses on wireless LANs.
Join Jim for discussions as he answers questions in the 802.11 Planet Forums.
