The human location estimation in indoor enjoinment with good accuracy is required in many health care, surviving, and monitoring activities. The available methodologies are not providing good estimation accuracy or based on making big change in the environment infrastructure. This book, describes the methodologies used for human localisation in an indoor environment based on the strength of radio frequency signal. The book contribution is development of three techniques for representing the signal strength map and extracting location of a user from these maps. A strategy based on a particle filter, fuzzy logic, and neural networks for localisation are evaluated. A series of experiments conducted in a real-life environment and the viability of using radio frequency signal strength for localisation has been investigated and future research directions also highlight it. The methods will help shed some light on this new and exciting localisation system, and should be especially useful to professionals in Communications and intelligent systems fields, or anyone else who may be considering utilizing real time built environment human location applications.