Network virtualization helps network on-demand provision and simplifies network scaling, workload and resource adjustments. This chapter examines the challenges and benefits of network functions virtualization network design. In the early phase of network virtualization, it was modest but then evolved by 3rd Generation Partnership Project to a key enabling technology in 5G networks. Network sharing in 5G has evolved from sharing the actual physical resources into sharing virtual wireless networks elements of the physical networks. Energy harvesting (EH) is important to support mobile user equipments with recharged batteries to keep their connectivity with 5G networks. The millimetre Wave bands are widely expected to be used for 5G cellular networks, they have two major attractions for wireless energy harvesting, namely: massive number of antennas, and highly dense base-stations deployments. EH-based cooperative sensing provides distributed sensors to enhance the uplink multiple access control protocol.