Cell-Loc's network-based wireless solution uses time difference of arrival (TDOA) to pinpoint the location of wireless devices. Specifically, hyperbolic multilateration. We "listen" to the radio frequency (RF) activity in an area and measure the infinitesimal time difference of signals reaching our "listening posts." We have a short Flash demonstration for you to view, explaining some of the applications for our technology. Get the free Flash player here.

Cellocate Technology Overview

• The Cellocate network is a stand-alone network. Whether locating the Cellocate Beacon or other wireless devices, the Cellocate network is independent from other wireless carriers.
• It is easily scaleable, meaning that as demand increases, additional operational capability can be added by simply adding modules to the chassis.
• Cellocate networks are deployed for coverage. In comparison, cellular carriers deploy their networks for capacity.

The basis of Cellocate is the very accurate measurement of time. As the RF signals travel at the speed of light, 300,000 kilometres per second, Cellocate measures transmissions at very accurate levels. For example, each 100 nanoseconds (0.0000001 second) represents 30 metres of distance.

At the network controller, Cellocate's software performs the TDOA analysis and interpolation followed by hyperbolic multilateration.

Cell-Loc's Network-based TDOA

Network-based refers to the fact that a series of terrestrially deployed "listening posts" collect data and send it to a centralized server that then calculates locations, versus a handset-based solution in which the wireless device or handset does the calculation using GPS positioning. TDOA positioning is accomplished by estimating the time of arrival (TOA) of wireless handset signals at a number of fixed sites of known geographical location.

The difference in TOA measurements at two cell sites defines a hyperbola on which the wireless device must lie. A measured TOA at a third cell site may be differenced with one of the first two TOAs to produce a second hyperbola. The intersection of the two hyperbolas then yields the position estimate of the wireless device. This method of positioning is called hyperbolic multilateration.

End-to-end location solution

Locating Assets and People

Cellocate Beacon^TM

The Cellocate Beacon^TM has been specifically designed to track assets and people. The Beacon is inherently a tracking device, rather than a navigational tool. As an integral part of the overall system, Cell-Loc has carefully designed the user device to be low-cost, while at the same time very reliable. In order to keep overall costs to the user low, the Beacon uses standard replaceable AA batteries that last for months - no need for expensive installation fees.