In a traditional Radio Access Network (RAN), the base station consists of both the Radio Unit (RU) and the Baseband Unit (BBU). The RU is responsible for radio signal processing, while the BBU handles baseband processing tasks.
In a Cloud RAN architecture, the BBUs are separated from the RUs and moved to a centralized cloud infrastructure. This separation allows for more efficient resource utilization, scalability, and flexibility.
Centralized Processing:
The baseband processing, which includes functions like modulation/demodulation, encoding/decoding, and channel coding/decoding, is moved to a centralized cloud data center.
Centralized processing enables the sharing of computing resources among multiple remote radio heads, leading to cost savings and improved resource efficiency.
Virtualization:
Cloud RAN leverages virtualization technologies, such as Network Function Virtualization (NFV) and Software-Defined Networking (SDN).
NFV allows the virtualization of network functions, and SDN enables the dynamic management and configuration of network resources.
Functional Split:
Cloud RAN introduces a functional split between the centralized BBU and the distributed RUs.
The fronthaul, which connects the RU to the BBU, carries digitized and compressed baseband signals. Common functional splits include options like the CPRI (Common Public Radio Interface) and eCPRI (enhanced Common Public Radio Interface).
Flexibility and Scalability:
Cloud RAN architecture provides greater flexibility in scaling network capacity. It allows for dynamic resource allocation based on the network's real-time demands.
Virtualization enables the rapid deployment of new services and the ability to scale resources up or down as needed.
Latency Considerations:
While centralization brings benefits, it also introduces challenges, particularly in terms of latency. Low-latency fronthaul networks are crucial to maintaining the real-time responsiveness required for mobile communication.
Cloud Infrastructure:
The centralized cloud infrastructure supporting Cloud RAN typically includes data centers with high-performance computing, storage, and networking resources.
Cloud infrastructure may be owned and operated by the telecommunication service provider or could be provided by third-party cloud service providers.
Advantages:
Cloud RAN can result in cost savings, as resources are centralized and can be shared among multiple remote radio heads.
It offers improved network efficiency, scalability, and flexibility.
Challenges:
Challenges include managing latency in the fronthaul, ensuring reliability, and addressing the increased complexity introduced by virtualized network functions.
