RTLS using WiFi – Ekahau RTLS

Over the last month, I have been talking to a number of vendors
in the Real Time Location Systems (RTLS) market. One of these
vendors is Ekahau, originally a Finish based company that has now
registered and headquartered itself in the US. I had a discussion
with Antti Korhonen, President and CEO, at the end of September
2007. Ekahau were founded in 2000 and were spun out of Complex
Systems Computation Group at the University of Helsinki. They
focused on the provision of positioning solutions for locating
people, assets, inventory and other objects using wireless
enterprise networks. Ekahau are headquartered in Saratoga,
California, with Helsinki as their development centre. The company
is privately owned by its employees, founders, and venture capital
and industrial investors.

For those of you who have not read previous articles I have
written on RTLS, let me first explain what an RTLS is. It is any
wireless technology that can be used to continuously determine and
track the real-time location of assets and personnel. RTLSs are
fully automated systems that continually monitor the locations of
assets and personnel. An RTLS solution typically utilises
battery-operated radio tags and a cellular locating system to
detect the presence and location of the tags. The locating system
is usually deployed as a matrix of locating devices that are
installed at a spacing of anywhere from 50 to 1000 feet. These
locating devices determine the locations of the radio tags.

Ekahau Real-Time Location System is a wireless radio frequency
solution that monitors and reports real-time locations of tracked
resources. Unlike competing solutions, which are based on Time
Difference of Arrival (TDOA) technology, Bluetooth or active RFID,
Ekahau’s patented RF modelling technology uses standard WiFi
access points. Thus by using standard 802.11 access points and
WiFi tags, any WiFi network can now work as the backbone and
sensor network for a real-time location system.

Ekahau RTLS consists of the following components:

• Ekahau Tracker, which is an end-user application for real-time
  tracking, dispatching alarms and analyzing the locations of assets
  and people.
• Ekahau Finder, which is an end-user application for grouping, locating
  and viewing the location of people and assets in real-time.
• Ekahau Engine, which is a service that runs on a dedicated Windows
  server. It provides the following functional elements:
  • A Location Engine (Ekahau Positioning Engine 4.1) for receiving
    signal strength measurements from tags, compares the measurements
    to an existing reference data and calculates accurate location
    estimates.
  • An Event Handler for receiving events such as tag-originated
    call button alarms or tamper switch alerts and routing them to
    designated applications.
  • Open application APIs for integrating 3rd party applications to
    the system. These provide location feeds, location queries and
    events to the application using industry-compliant standards.
  • Ekahau Location Survey for recording reference data during the
    deployment phase.

• Ekahau WiFi Tags, which are active radio tag for tracking and finding
  people and assets.
• Ekahau Client, which is a software agent that can be used to
  location-enable wireless devices. It works similarly as Tags but
  runs in the background on existing PDAs, Tablet PCs or
  laptops.

Ekahau RTLS can get up to a 1–3 meter average resolution in an
optimal environment with enterprise grade WiFi network. For the
best accuracy, Ekahau recommends that at least three audible access
points with at least -75DBM RSSI are available at any given
location. Ekahau RTLS can work outdoors, as long as there is AP
coverage. Ekahau state that they can achieve a location resolution
of up to 5–10 meters in outdoor areas.

Ekahau have clear targets in terms of industry sectors, with a
number of customers in the Healthcare and Mining sectors. Other
verticals are people tracking and supply chain asset tracking.

In terms of partner support, Ekahau have a partner programme in
place that provides development, marketing and sales support to
certified Ekahau System Integrators, VARs and OEMs. In addition,
there are OEM and VAR agreements. An unusual agreement is the LBE
(Located by Ekahau) Agreement, which allows a partner to
location-enable WiFi products with free Ekahau client software to
be embedded in a device.

Ekahau RTLS is a product Bloor feel should be on the evaluation
list of any organisation looking at RTLS, especially if they have
existing WiFi networks in place.