[27, 35]. Consequently, in 5G networks, an E2E virtualization is considered to virtualize the CN, RAN, backhaul, spectrum, and air interface [3, 5, 27]. By adopting SDN and NFV concepts within C-RAN, the 5GC manages and orchestrates the network services and replaces the dedicated hardware solutions with virtualized software. In [37], an architectural framework for V-CRAN was illustrated that is composed of radio unit (RU), digital unit, virtual-BS (V-BS), and time-wavelength-division multiplexed passive optical network (TWDM-PON). The RU is responsible on transmitting and receiving the data. Meanwhile, the V- BS virtualizes the resources in the cloud digital unit. The digital unit, in turns, is responsible on the baseband processing and the functions of L2/L3. Furthermore, the TWDM-PON is a fronthaul solution to connect the RU with the digital unit in V-CRAN at low latency, cost, and energy consumption [37]. In [38], an architecture for SDN called SoftAir has been proposed that employs SDN and NFV concepts to provide a scalable and flexible C-RAN architecture. Adopting SDN and NFV 1 A Comprehensive Study on 5G concepts within C-RAN introduces several benefits for C-RAN in terms of: 1. Optimizing the network resources by employing a dedicated resource to an application or service. 2. Simplifying the management of end-user devices by decoupling the UP and CP where these devices serve as packet-forwarding units, while the CP will be processed by an external controller. 3. Softwarization of the network by running the functionalities of the SDN con- troller and the BBU pools on NFs separated from the underlying hardware. 4. Plug-in and play by self and quick initialization and configuration of NFs. 5. Reducing the cost by softwarization and optimization of the network resources. Despite the several benefits of V-CRAN, it still faces challenging issues. Several challenges for V-CRAN have been discussed in [3, 27] and [36] in terms of latency and heterogeneity of fronthaul links, unified protocol, security and privacy, 