Introduction

In this information era people are living in a society in which processing, flow and exchange of information are vital for their existence. Two major issues in such society, which are related to flow and exchange of information, are connectivity and mobility. On one hand, computers and Internet provide connectivity and allow communication as well as fast access to large amounts of information. On the other hand, wireless technologies bring mobility. People can move and still be able to communicate and have access to various kind of information. Therefore, the functioning of an information society is unthinkable without the use of computers, Internet and wireless technologies. The expectations are that in the future they will merge into a unique system for communication, access to information as well as their exchange and processing.