Dynamically Extending the Reach of Wireless Networks in Determining Movement of Individuals Between Cells

Abstract — Location Based Systems are now a ubiquitous part of everyday life, seamlessly assisting us in everything we do from driving our cars to finding a cab, even preventing us missing our bus or train stop when oversleeping whilst on one. Global Positioning System (GPS) being the culmination of research in this area, and the technology of choice for outdoor location based systems today. Since then there have been significant inroads made in the development of Indoor Positioning Systems that attempt to mirror the success of its outdoor big brother equivalent. There are however some obvious barriers that currently stifle this aspiration, primarily the topography of an indoor location with its many walls, doors, pillars, ceilings and floors, distorting the signals to\from mobile devices and their tracking devices. The characteristically noisy behavior of wireless channels, Bluetooth devices, cordless phones, microwaves etc. can cause interference as they all operate in the same band as Wi-Fi devices, namely 2.4 GHz, while water and human bodies absorb RF signals at that frequency. Furthermore the limited range of tracking devices such as Wireless Access Points (APs), and the restrictions surrounding their positioning within a building further exacerbate this issue. This paper advocates a solution to some of these issues, proposing a method to extend the range of Indoor Location Based Systems using Mobile Devices at the extremities of Cells who ‘know ’ their location, to determine the location of devices beyond the Cell range of the AP. Keywords- Localisation; Indoor positioning; Indoor localisation; geographical positioning; wireless; GPS