Cristiano di Flora Massimo Ficco Stefano Russo Vincenzo Vecchio Indoor and Outdoor Location Based Services for Portable Wireless Devices. 244-250 2005 conf/icdcsw/2005 ICDCS Workshops http://doi.ieeecomputersociety.org/10.1109/ICDCSW.2005.77 db/conf/icdcsw/icdcsw2005.html#FloraFRV05