Research challenges for 5G cellular architecture

Due to the centralized architecture of current cellular networks, the wireless link capacity as well as the bandwidth of the radio access and backhaul networks cannot practically cope with the exponential growth of mobile traffic. In order to meet this challenge, researches on the fifth generation (5G) cellular systems are highly anticipated in the next decade. Advanced technologies such as massive antennas and millimeter-wave systems, as well as direct communications will have significant impact on design of new heterogeneous network architecture. Cloud computing has emerged as a promising solution for providing high energy and spectral efficiency across software defined radio networks, in which the virtualization of communication hardware and software elements place stress on architecture and protocols. This paper analyses the main challenges raised by the new vision of cellular architecture, particularly focusing on issues related to the key emerging radio technologies, direct communications, cloud computing, as well as support of massive access.