Metropolitan area mobile services to support virtual groups

More and more cities and municipal organizations start to offer services restricted to their metropolitan area. Today, many of these service are located in the field of e-government, allowing citizens to perform many of their administrative duties online. However, with wireless networks and mobile devices becoming more powerful and much less expensive, a broad variety of new mobile services can be envisioned. In this paper, we investigate metropolitan services to support mobile virtual groups, i.e., groups of mobile users who have some kind of logical association with each other, but who are distributed throughout the city and are mobile, meaning they might be constantly on the move. As two major services that such groups would like to make use of, we identified voice group communication and localization of group members. In mobile environments, both services pose a number of problems. Based on a typical metropolitan area network infrastructure, we develop solutions for these problems. We also show how these solutions can be integrated into a mobile group application, namely, the communication and localization component of a virtual tourist guide for the city of Heidelberg using members of a tourist group which can move independently but still keep in touch. We also describe measurements and experiences to argue for the feasibility of our approach.