Edinburgh Napier University

  Location based services are a diverse and growing set of related technologies which may be used to provide tracking and location awareness. LBS are employed in both fixed and mobile networks. A concise overview of the development of LBS, and some of the operational issues is presented. Seen from the physical layer, LBS are constrained by multipath interference, low signal to noise power, and channel fading. LBS methodologies including cell-ID, prediction (dead-reckoning), angle of arrival (AOA), time of arrival (TOA) and observed time difference of arrival (TDOA), hybrid AOA-TOA localization and localization by finger printing are summarised. There are two principal areas of constraint to be addressed, (1) in the service segment, practical and legal issues related to the subscriber privacy require development and clarification; and (2) the ability to deliver real time data, and measure the associated mobility of a subscriber (or target) with the required level of precision.