## 7 Proposed Architecture for Cellular System Based on SDN, NFV, and C-RAN
### Interaction Between SDN Controller, NFV MANO, and C-RAN  
The SDN controller is responsible for effectively managing the network resources and data flow across the network infrastructure, while the network functions within the core control plane have their specific roles in managing different aspects of the network's  
Figure 17: 5G proposed architecture based on SDN, NFV, and C-RAN. Core and RAN network functions can be partially or fully virtualized based on the requirement. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Architectural Component** & **Solved Challenge** & **Technical Approach** & **Validation** \\ \hline Cellular Architecture with & & & \\ SDN Controller & Dynamic QoS Provisioning & OpenFlow/PlRuntime Programability & Google’s SDN Deployment [65] \\ \hline Virtualized Core Functions & & Hardware Dependency & NFV MANO Lifecycle Management & 38\% Energy Swiring in 5G Core [93] \\ \hline BBU Pool with PHY/MAC Split & Fronthaul Capacity vs. Latency Tradeoff & O-RAN/C-RAN & Mavenir’s Open VRAN [14] \\ \hline NFV-Manged RRUs & RAN Virtualization Overhead & In-line Acceleration for L1 Processing & Samsung’s 22\% DU Power Reduction [143] \\ \hline SDN-NFVO Integration & Multi-Vendor Interoperability & Standardized ETSI Interfaces & OPNVT Tested Results [101] \\ \hline Hierarchical Resource Pool & Energy-Inefficient Resource Fragmentation &
\begin{tabular}{c} Dynamic VNF Scaling Plus C-RAN \\ Load Balancing \\ \end{tabular} & 83\% BBU Energy Swiring [128] \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Architecture components and their solutions to key challenges. signaling and control logic, as shown in Figure 17. Here is how the SDN controller and network functions interact and manage the network functionality:  
* **C-RAN Management:*
* Centralization: The SDN controller can centralize the control of the C-RAN infrastructure, allowing for the pooling of BBUs that can be dynamically assigned to RRUs based on the current network load and demand. * Network Optimization: Through the SDN controller, the network can optimize the routing of traffic between the RRUs and BBUs. It can also manage the split of control and user plane functions to improve performance and efficiency. * Dynamic Configuration: The SDN controller enables the dynamic reconfiguration of network resources in response to changing traffic patterns. This will help C-RAN to allocate and reallocate radio resources in real-time. * **NFV Management:*
* Oversees the Underlying Network Infrastructure: In the proposed architecture, the SDN controller does not directly handle the core network functions. Instead, it oversees the underlying network infrastructure. This infrastructure allows various network functions such as signaling, session management, and authentication to communicate with each other and with the radio access network. The SDN controller ensures that the data plane where actual data flows aligns smoothly with the control plane where decisions are made, resulting in an efficient and agile network [104]. * Interconnectivity: Figure 18 shows the layered architecture of the integration of SDN and NFV systems. It is similar to SDN architecture and consists of infrastructure, control, and application layers. It utilizes the principle of NFV to facilitate the implementation and management of network functions. The SDN controller orchestrates network resources to ensure proper communication among VNFs. Under the management of the VIM, the controller can modify network behavior as required, responding to network user requests [97]. The SDN controller and NFV MANO work together to improve network services. SDN enhances NFV by providing better traffic steering and service chaining. MANO is responsible for managing and orchestrating the virtual network resources and connections between VNFs for a complete network service. This requires the SDN controller and MANO to collaborate for efficient traffic routing [104].