s reduce TCO and become greener. Depending on the type of the resources being virtualized and the objective of virtualization, three different generic frameworks can be identified for wireless virtualization [34]: 1) Flow-based virtualization deals with the isolation, schedul- ing, management, and service differentiation between traffic flows, streams of data sharing a common signature. It is inspired by the flow-based SDN and network virtualization but in the realm of wireless networks and technologies. Thus, it requires wireless-specific functionalities such as the radio resource blocks scheduler to support QoS and SLA over the traffic flows. 4 MVNOs [35] are a new breed of wireless network operators who may not own the wireless infrastructure or spectrum, but give a virtual appearance of owning a wireless network. Basically, MVNOs resell the services of big operators, usually lower prices and with more flexible plans. Virgin Mobile is an example for MVNO. 2 Virtualization and Cloud Computing 2) Protocol-based virtualization allows to isolate, customize, and manage multiple wireless protocol stacks on a single radio hardware, which is not possible in flow-based virtualization. This means that MAC and PHY resources are being virtualized. Consequently, each tenant can have their own MAC and PHY configuration parameters while such a differentiation is not possi- ble in a flow-based virtualization. The wireless NIC5 virtualization [38, 39] where IEEE 802.11 is virtualized by means of the 802.11 wireless NIC, falls into this category. 3) RF frontend and spectrum-based virtualization is the deepest level of virtualization that focuses on the abstraction and dynamic allocation of the spectrum. Also, it decouples the RF frontend from the protocols and allows a single frontend to be used by multiple virtual nodes or a single user to use multiple virtual frontends. The spectrum allocation in the spectrum-based virtualization differs from that of the flow-based virtualization for its broader scope and potential to use non