In Distributed Radio Access Networks, the processing power of the node is spread to keep the network running over many independent base stations. D-RAN base stations are designed to be independent and self-contained with each one having the ability to send, receive, capture and process the communications by themselves. D-RAN Architecture is very expensive to install, expand and maintain which has a significant impact on the CAPEX and OPEX of the telecom companies.
In a D-RAN architecture, the whole base station is located at the cell tower site. The RRUs are located at the top of the base stations and the BBUs are located in an equipment room that is not too far from the base station. The RRUs and BBUs are connected with the CPRI (Common Public Radio Interface).