Ekahau's Positioning Engine 2.0

By Jim Geier

December 20, 2002

Ready to pinpoint the location of all the users on your WLAN within a few feet? Once through the laborious setup and if you have enough access points to provide accuracy, Ekahau's technology can have you mapping client in no time.

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.



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