ABSTRACT
The current telecommunications environment is facing a data storm with Cisco predicting that by 2020 the number of Internet protocol (IP)-connected devices will reach three times the global population, generating up to 25GB of IP traffic per capita [1]. In this context, the network operators are facing different challenges on how to meet the required coverage and capacity of their networks, how to deal with interferences, and how to manage the increased complexity and deal with higher capital expenditure (CAPEX) and operating expenditure (OPEX). To this extent, in order to cope with all these issues, the next generation of wireless systems could make use of various new solutions and technologies, such as software-defined networks (SDNs) and network function virtualization (NFV), which help the network operators to reduce their CAPEX intensity by transferring their hardware-based network to software- and cloud-based solutions; Wi-Fi and femtocell opportunistic offloading techniques for mobile traffic; cloud radio access networks (C-RANs), which offer a centralized, cooperative, clean (green), and cloud computing architecture for radio access networks (RANs); and higher spectral efficiency by using advanced receivers with interference cancellation or advanced coding and modulation solutions such as the non-orthogonal multiple access (NOMA) technique.
