Future communication systems will be characterized by their needs for increased flexibility, high data rate, efficient use of the fragmented spectrum, and bandwidth-efficient handling of unsynchronized users. Heterogeneous networks (HetNet), with co-existent systems of different bandwidth characteristics, both cell-based and ad-hoc, should also be accommodated. Such scenarios include cognitive radio (e.g., the TV white space (TVWS) system) and the co-habitation of broadband data services with narrowband professional mobile radio (PMR) channels to efficiently relieve the spectrum scarcity.
Edited by: Faouzi Bader, Fredric Harris, Eleftherios Kofidis, Markku Renfors and Pierre Siohan