Personal and ubiquitous computing: special issue on location and context awareness

location information, which is one important aspect of ubiquitous computing. In all its facets like user mobility, terminal and session mobility it requires advances in wireless, ad hoc and selforganizing network technologies and smart sensors and devices. Furthermore, the development of infrastructures becomes more and more important for supporting cognitive environments, as well as discovery and execution frameworks for location-aware services. Context-awareness, a generalization of locationawareness, is another driver of the ubiquitous computing paradigm. Well-designed context modeling and context retrieval approaches are key prerequisites in any context-aware system. From the technical side, sensing, fusing and distributing location and other context information is as important as providing context-awareness to applictions and services in ubiquitous systems. The first International Workshop on Locationand Context-Awareness was held in cooperation with the third International Conference on Pervasive Computing 2005 in Oberpfaffenhofen/Munich, Germany. The workshop was organized by the Institute of Communications and Navigation of the German Aerospace Center (DLR), Oberpfaffenhofen, and the Mobile and Distributed Systems Group of the Ludwig Maximilian University of Munich. A total of 84 papers from 26 countries were submitted, from which 26 full and 7 short papers were selected for publication in the proceedings, printed in the Lecture Notes in Computer Science Series, Volume 3479 by Springer. During the workshop, novel positioning algorithms and location sensing techniques were discussed, comprising not only enhancements of singular systems, like positioning in GSM or WLAN, but also hybrid technologies, such as the integration of global satellite systems with inertial positioning. Furthermore, improvements in sensor technology as well as the integration and fusion of sensors were addressed both on a theoretical and on an implementational level. Personal and confidential data, such as location data of users, have profound implications for personal information privacy. Thus privacy protection, privacyoriented location-aware systems, and how privacy affects the feasibility and usefulness of systems were also addressed in the workshop. By organizing this special issue, we present recent and significant developments in the area of location and context awareness. The articles that this special issue features have been selected from the presentations given at this first Workshop on Location and Context Awareness. Nine Authors were asked to extend their articles based on the discussion and comments made during presentations at the workshop and their latest findings. These submissions have been reviewed once more by, 2–3 reviewers. And finally, seven of these papers have been selected for the publication in this issue. We would like to thank the authors who submitted their articles to this special issue. In addition, we would like to thank the referees for their time and efforts to review these submissions. C. Linnhoff-Popien (&) T. Strang (&) Munich, Germany e-mail: linnhoff@ifi.lmu.de