In a pervasive computing environment, the availability of accurate and up-to-date maps of buildings and their internal spaces is essential for enabling location based commercial and emergency services. However, these maps are expensive to make and maintain. Traditional methods of mapping buildings rely on blue prints or drawings. Some problems with prior art methods are the difficulty of obtaining an accurate map to begin with, and the high cost of maintaining an accurate map over time. For example, employees in an office building frequently change their office or cubicle locations, certain offices may be physically eliminated, corridors may be added or removed, and new offices are continually added. The net result is that using physical maps to route users through a building will nearly always be inaccurate and out of date. The problem is especially acute in large, multi-story buildings such as government offices, corporate headquarters, etc. New employees or visitors who are not familiar with the layout of a facility have a particularly difficult time navigating these buildings. Although navigational systems for use in outdoor environments, such as hiking, driving, etc. have been commercially available, they all rely on manually digitized maps that are input to the system. While the input of such a large amount of data is a daunting task, it is a task that only needs to be performed once, as buildings, roads, cities, contains and other large physical structures in the outdoor environment rarely, if ever, move or disappear. However, this is not the case for the indoor environment, where scale is smaller and geography is dynamic. It would be a desired addition to the art if an easy, inexpensive method of dynamically creating map data could be used to guide individuals through buildings.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity showing only those specific details that are pertinent to understanding the embodiments of the present invention.