 to Network densification concept increases the number of BSs in a given area. M. Alfaqawi et al. increase the network capacity and provide high QoS. The SCs communicate with the BBU pool via wireless or wired fronthaul, while the macro-cell communicates with the BBU via X2/S1 backhaul interface [5]. On the other hand, centralized and shared resources of C-RAN facilitate the decoupling of the user plane (UP) from the control plane (CP), i.e., SDN concept [27, 56]. In H-CRAN, the SCs can handle the user data, while the macro-cell manages the control signaling [5]. The splitting of control and user planes improves the network management and reducing the signaling on the fronthaul [3, 5]. In addition, in H-CRAN, the cross-tier interferences between the LPN and HPN can be managed by cloud computing- based cooperative RRM (CC-CRRM) [30]. Despite the benefits of H-CRAN on the QoS, it faces several challenges and issues in terms of optimal planning to avoid interference, energy consumption, and demanding a low latency and high capacity fronthaul and backhaul links [3, 29, 32]. 1.2.1.2 Virtualized C-RAN (V-CRAN) In 2012, the telecom operators observed several problems to launch new network services due to the heterogeneity, multiplicity, different proprietary, and short life cycles of the network hardware. Consequently, virtualization of infrastructure and computing resources has been studied widely, in the literature, thanks to several benefits of providing scalable, multi-tenancy, and cost-effective solutions compared to dedicated hardware at the cell site [60]. Virtualization concept decouples the network functions (NFs) from the underlying hardware and running them as virtual machines (VMs) or containers [61, 62]. In [34], virtualization of wireless networks has been considered with layer L3 in E-UTRAN protocol stack that connects the BSs into the core network (CN). In addition, ETSI in [34] discussed the virtualization of layer L2 in E-UTRAN operated on the BS. Currently, virtualization has been investigated for L1 