What is Time of Arrival (TOA)

The term “mobile era” as a characterization of the 21st century can hardly be considered an exaggeration (Kalakota & Robinson, 2001). Mobile phones are the fastest penetrating technology in the history of mankind, and global mobile phone ownership has surpassed even the ownership of fixed phones. Mobile applications, despite potentially being very different in nature from each other, all share a common characteristic that distinguishes them from their wire-line counterparts: they allow their users to move around while remaining capable of accessing the network and its services. In the mobility era, location identification has naturally become a critical attribute, as it opens the door to a world of applications and services that were unthinkable only a few years ago (May, 2001). The term “mobile location services” (MLS) [or “locationbased services (LBS), as they are sometimes also referred to] has been coined to group together applications and services that utilize information related to the geographical position of their users to provide value-adding services to them (Rao & Minakakis, 2003). This article provides a concise introduction to the major types of MLS and also introduces the reader to the most important positioning technologies that render the provision of MLS possible. Finally, the article also introduces a number of issues that are critical for the future of MLS, including privacy protection, regulation, and standardization.