TABLE OF CONTENTS Defining a sound technical framework for future 4G wireless systems and determining the appropriate enabling technologies is undoubtedly a colossal task, requiring open discussions and collaboration among a large number of parties. Key players in this multiyear development process are manufacturers, academia, wireless operators, service providers, regulatory bodies, and governmental agencies, working on their own and in collaborative projects. Currently, many activities are being conducted that aim not only at defining future 4G systems but also at determining the most promising technical solutions for implementing such systems. In this chapter research initiatives and development work focused on 4G systems are introduced and briefly discussed. First, the scope and goals of the most relevant large-scale research initiatives dealing with 4G will be briefly described. Then, the development work currently being undertaken mainly by industry to develop concrete 4G solutions is described. 4G development work is highly fragmented, and, in general, the work scope of each organization varies greatly, depending on its core business and size. Current efforts can be regarded as being part of a preceding stage to the upcoming 4G standardization process, hence the importance of these activities.
In this section the most prominent research initiatives on 4G systems are presented. Particularly attention is given to wide-scope multipartner projects aiming to achieve a global footprint. Based on the number and size of ongoing projects, and taking into account the number of participating partners, Asia and Europe appear to be more involved...
