TABLE OF CONTENTS Mobility support of mobile wireless systems naturally leads to location-aware computing that encompasses a number of techniques, protocols, and enabling mobile wireless technologies and mobile devices utilizing an object's location information to provide augmented consumer- or business-oriented applications and services namely, location-based services (LBSs). To mobile service providers, LBSs seem to be good candidates for value-added services that have the potential to grow significantly as more location-aware mobile devices and network capabilities are being used. An object's location is indeed a key component of context, meaning that location-aware computing is actually concerned with making a mobile wireless system context aware in terms of location. Location-based services and applications are therefore the first step toward context awareness in a pervasive mobile computing environment. The role of smart phones in the context of location-aware computing is crucial, as a smart phone is very likely to have multiple wireless interfaces; thus, with some supporting software, a smart phone could be used as a location-sensing device for object localization.
We begin our discussion with two fundamental issues of location-aware computing: location representation and localization. The first issue is concerned with choosing the best location data model for a location-aware computing system, whereas localization is generally defined as involving location determination schemes and algorithms. Enabling technologies for localization in the wireless world are referred to as location sensing technologies, including global positioning systems (GPSs), cellular base stations, wireless local area networks (LANs), ultrasound, radio frequency identification (RFID) tags, and wireless sensor...
