Welcome to the proceedings of the 4th International Conference on Wired/ Wireless Internet Communications held at the University of Bern from May 10 12,2006. As in 2005, WWIC was selected as the o?cial conference by COST Action 290, and Springer accepted to publish the conference proceedings in the LNCS series. These facts have helped to again attract a large number of hi- quality paper submissions. We received 142 submissions out of which 29 papers were selected by the International Program Committee for presentation at the conference. This resulted in a low acceptance rate of 21%. To limit...