Luigi Ceccaroni Victor Codina Manel Palau Marc Pous PaTac: Urban, Ubiquitous, Personalized Services for Citizens and Tourists. 7-12 2009 ICDS http://dx.doi.org/10.1109/ICDS.2009.25 conf/icds/2009 db/conf/icds/icds2009.html#CeccaroniCPP09