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Abstract
GPS technology has revolutionized outdoor navigation, but its long-range radio signal cannot successfully be accessed within the confines of a building. Indoor Positioning Systems (IPS) exist to provide a similarly useful solution for navigating complex indoor environments. However, current IPS technologies are plagued by two major problems. Existing systems are either prohibitively expensive to install or lack the accuracy to be deemed effective. We propose a new system that will overcome these obstacles by utilizing a Reduced Signal Strength (RSS) Algorithm that utilizes data from the structure's architecture to more accurately triangulate the user's location.
1. Introduction
For the purpose of this study, we defined an Indoor Positioning System (IPS) as a set of technologies used to determine the location of a user within some defined structure. Unlike well-known GPS technologies, IPS has not been applied on a widespread basis. It has, however, been utilized by the Smithsonian Institution to provide visitors with electronically guided tours of the museum (Sulick, 2012), and by shopping centers, including Hong Kong's Tai Po Mega Mall (Kopytoff, 2013), to aid shoppers in locating their favorite stores.
Perhaps the primary reason that IPS technologies have not experienced more widespread use is that, once again unlike GPS, there is no accepted standard for the implementation of such systems. In today's marketplace, there are two leading solutions for commercially available indoor positioning systems. In the upcoming segments, we will address the shortcomings of those systems before outlining a proposed solution.
2. Infrared (IR)
The most common positioning systems utilize Infrared light to offer absolute position estimation (Gu, 2009). One of the earliest examples of these systems is the Active Badge positioning system invented at AT&T Cambridge in the 1990s (Gu, 2009). Each active badge, intended to be worn by people inside the given building, transmits a unique IR signal every 15 seconds (Gu, 2009). Sensors are placed at each location within the coverage area of the system, and these detect the IR signal sent by the active badges (Gu, 2009). The position of the active badge may then be determined to room level accuracy from information received from the sensors (Gu, 2009).
The largest problem faced by all IR-based systems is that they require direct line of sight for the...