How do I design a location-dependent application? Filipe Meneses * , Adriano Moreira * , Rui José * Information Systems Department, University of Minho ABSTRACT The generalisation of the Internet and the recent technological developments in embedded systems and wireless networks contribute to the realisation of a vision where access to information is possible at any moment and from anywhere. This is particularly attractive with information that is relevant to a specific geographic location. Applications that rely on location- based services to provide information to mobile users, or that support interaction with real devices in the user neighbourhood, are called location-dependent applications and enhance the relationship between mobile users and a specific geographic location. However, the design of such applications breaks with the existing paradigms and methodologies as the mobile devices and the wireless communication infrastructures have characteristics that are very different from those of desktop computers and wired communication systems. The Around architecture is an open and extensible framework for location-based services that allows network services to be associated with specific geographic locations. By using this architecture applications can select services that are relevant for specific locations. Within the context of the Around project we have developed a prototype system with multiple location- based services and an application that accesses these services to provide information related to a town transportation system. This paper reports on the design and development of this location-based application. Its design raised several new issues, going from the computational model to the interface paradigm, which are also discussed in this paper. The developed application is composed of several modules: a set of agents which are autonomous units with the knowledge necessary to select and use location-based services in a specific thematic area (e.g. transportation); an HTML output area based on a browser metaphor; and a location-context module responsible for determining the user context. The results show that an application architecture based on a modular approach turns to be very flexible as it becomes very easy to extend its functionality by simply adding or changing the agents that deal with each location-based service. Keywords: Location-based services; Location-based application; Mobile computing; Context-aware applications 1. INTRODUCTION The Internet is getting bigger every day, with more web pages, more services and more information available. While the prevailing access model to the Internet is still based on a desktop PC, technological development is rapidly enabling access from everywhere, using mobile devices equipped with wireless network interfaces. The geographic location of mobile users is also becoming increasingly available through several location technologies, such as Global Positioning System (GPS) or location systems based on cellular networks. This scenario is triggering the development of a new set of services and applications known as location-dependent. Location-based services are those services that are only relevant to a specific geographic location, i.e., that are available only to those users located inside the area of application of the services. Because the actual conceptual schema of the Internet does not support the association of services to geographic locations we have developed and used a new architecture – the Around architecture. The Around is a generic, flexible and scalable architecture for location-based services 1 . * {meneses, adriano, rui}@dsi.uminho.pt; phone: +351 253510148; fax: +351 253510250; Information Systems Department, University of Minho, Azurém, 4800-058 Guimarães, Portugal. http://www.dsi.uminho.pt/get/