Nov/Dec 2004

If you thought you'd got all types of tracking mentally compartmented, prepare for another. The latest development in remote people and asset tracking is actually to track them within the confines of a Wi-Fi wireless network area, using the Wi-Fi technology to provide positioning information.

Location-based services that rely on knowing when users are in a given Wi-Fi zone are already offered by suppliers such as Appear Networks. Tracking within zones is a further refinement, and has been made a particular speciality by a California-based company called Ekahau, which has developed a suite of systems providing precise real-time location of Wi-Fi based mobile devices such as wireless laptops, PDAs and Wi-Fi tags. The object is to pinpoint them within the Wi-Fi coverage area, and feed to information out to people running and asset tracking applications.

Why would you want to do this? One reason is if you're actually working on the development of the Wi-Fi networks themselves, and want to measure signal strengths, data transfer rates and so on. Ekahau offers a range of software programs under the Ekahau Site Survey name to help with this kind of activity.

However, the company also envisages much more practical applications such as finding personnel in busy corporate environments such as hospitals, large office complexes, factories, warehouses and similar industrial locations using Wi-Fi extensively.

 

The system is run by the Ekahau Positioning Enginer 3.0, and uses the Wi-Fi devices themselves to capture location information. It is said to be accurate to within 1 metre. Where people without Wi-Fi devices need to be tracked, they carry what is know as an Ekahau T101 Wi-Fi tag (a battery-powered active radio tag).