The continuous and very intense development of IT has resulted in the fast development of computer networks. Computer networks, as well as the entire fieldofIT,aresubjectto constant changes triggered by the general technological advancement and the influence of new IT technologies.These methods and tools of designing and modeling computer networks are becoming more advanced. Above all, the scope of their application is growing thanks to, for example, the results of new research and because of new proposals of application, which not long ago were not even taken into consideration. These new applications stimulate the development of scientific research, as the broader application of system solutions based on computer networks results in a wide range of both theoretical and practical problems. This book proves that and the contents of its chapters concern a variety of topics and issues. Generally speaking, the contents can be divided into several subject groups. The first group of contributions concerns new technologies applied in computer networks,particularlythoserelatedto nano,molecularandquantumtechnology.