IEEE ACCESS Special Section Editorial: Recent Advances in Cloud Radio Access Networks

The demand for high-speed data applications, such as high-quality wireless video streaming, social networking, and machine-to-machine communication, has been growing explosively over the past 20 years and it is envisioned that asymmetric digital subscriber line-like user experience will be supported in the next generation wireless networks. The fifth generation (5G) system deployed initially in 2020 is expected to provide about 1000 times higher wireless area capacity and save up to 90% of energy consumption per service compared with the current 4G system. Furthermore, more than 1000-Gb/s/
$\mathrm{km}^{2}$
area spectral capacity in dense urban environments, 10 times higher battery life time of connected devices, and 5 times reduced end-to-end latency are expected in 5G systems. To meet such challenging goals, there is an urgent need for a revolutionary approach involving new wireless network architectures, as well as advanced signal processing and networking technologies.