It's not triangulation at all.
That's about the first thing that Tuomo Rutanen, the VP Business Development for Ekahau told me after he described the application that the company addresses for enterprises. In my defense, triangulation was the first thing I thought of considering the way mobile operators have to deliver location data to meet 911 compliance requirements.
Ekahau resellers and customers first upload a map into the software and walk about their offices, hospitals and warehouses with a laptop loaded with the Ekahau Site Survey scanning software. Every so often they report where they are by clicking (with the mouse) on the screen to indicate the physical location they're at. The site survey software checks the Wi-Fi driver's signal strength and maps or 'fingerprints' that result with the map of the office, hospital or warehouse.
Devices to be tracked report their Wi-Fi signal strength to the Ekahau server which reports location in an AJAX-based mashup. The server software correlates the signal strength with the coordinates on the map. In this way, leveraging patented research from Helsinki University, the company is able to offer enterprises a powerful tool in managing location-based services and functions for PCs, Polycom (SpectraLink) Wi-Fi phones and specially developed tokens (priced in the $30-$50 range depending on volume) that are shaped in employee ID badge, as barnacles attached to wheelchairs, medical equipment or other assets.
The software is priced on a per device-to-be-tracked basis.
This is location-based applications, without GPS, without RFID radio systems, able to leverage the low cost and ubiquity of Wi-Fi environments. Deploying a panic button on the tokens signals to the server (and to the supervisor monitoring the workflow) the presence of a problem. This one way emergency button press could be an inventory stockout, an employee safety issue or job completion notification. The key industries where Ekahau is focusing this application include health care, military logistics, manufacturing and mining, oil and gas. In these cases the employees and resources can be mis-located, placed in dangerous circumstances or resupplied on request.
It won't be long and we'll be seeing this technology applied to the consumer market – Do you know where your TV remote is?
