The Colloquium on Structural Information and Communication Complexity (SIROCCO) is an annual meeting focused on the relationship between comp- ing and communication. Over its 11 years of existence, SIROCCO has gained a considerable respect and has become an acknowledged forum bringing together specialists interested in the fundamental principles underlying all computing through communication. SIROCCO 2004 was the 11th in this series, held in Smolenice Castle, June 21-23,2004.PreviousSIROCCOcolloquiatookplaceinOttawa(1994),Olympia (1995), Siena (1996), Ascona (1997), Amal? (1998), Lacanau-Ocean (1999), L'Aquila (2000), Val de Nuria (2001), Andros (2002), and Umea(2003). The colloquium in 2004 was special in the respect that, for the ?rst time, the p- ceedings were published in the Lecture Notes in Computer Science series of Springer-Verlag. SIROCCO has alwaysencouragedhigh-quality researchfocused on the study of those factors which are signi?cant for the computability and the communi- tion complexity of problems,and onthe interplay betweenstructure, knowledge, and complexity.It covers topics as distributed computing, mobile computing, optical computing, parallel computing, communication complexity, information dissemination, routing protocols,distributed data-structures, models of com- nication, network topologies, high-speed interconnection networks, wireless n- works, sense of direction, structural properties, and topological awareness. The 56 contributions submitted to this year's SIROCCO were subject to a thorough refereeing process and 26 high quality submissions were selected for publication. WethanktheProgramCommitteemembersfortheirprofoundandcarefulwork. Our gratitude extends to the numerous subreferees for their valuable refereeing. We also acknowledgethe e?ort of all authors who submitted their contributions.
