As the mobile telecommunications industry barrels toward the 5G future, the amount of data traffic traversing networks is exploding. One of the ways network operators are coping with the reality and the preparation for the further onslaught that will come with 5G is to transform the radio access network (RAN). Which in essence, means centralizing it or placing it in the cloud.
The C-RAN (or Cloud RAN), also known as the Centralized RAN, is cheaper for operators in terms of capex and opex. However, it’s still early in the C-RAN development.
C-RAN (or Cloud RAN) Architecture
A C-RAN architecture has three primary components — a centralized baseband unit (BBU) pool, remote radio unit (RRU) networks, and transport network or fronthaul:
- BBU pool — The BBU pool, located at a centralized site, functions as a cloud or a data center. Its multiple BBU nodes dynamically allocate resources to RRUs based on current network needs.
- RRU network — The wireless RRU network connects wireless devices similarly to access points or towers in traditional cellular networks.
- Fronthaul/transport network — Using optical fiber communication, cellular communication, or millimeter wave (mmWave) communication, the fronthaul is the connection layer between a BBU and a set of RRUs, providing high-bandwidth links to handle the requirements of multiple RRUs.
The C-RAN can lower the total cost of ownership (TCO) and it can improve network performance. It is particularly beneficial in low-latency network scenarios. The centralized cloud RAN architecture also provides the benefit of not requiring a rebuild of the transport network.
Other benefits of C-RAN include the ability to pool resources, reuse infrastructure, simplify network operations and management, support multiple technologies, reduce energy consumption, and lower capex and opex. The network also becomes more heterogeneous and self-organizing. Once implemented, the C-RAN will bring other benefits, such as easier and faster network deployments and increased network flexibility.
The C-RAN architecture lets operators co-execute RAN functionalities along with other network functions in a data center environment, granting them the ability to more quickly offer new services over the mobile broadband network.