Baseband Unit (BBU) manage digital processing while the Remote Radio Unit (RRU) deals with of the analog side of things. The blend of both units at the cell site is known as Distributed-RAN (D-RAN) architecture. D-RAN introduced a few issues for telecoms particularly as far as dealing with the space and limit required at the base stations. In a D-RAN architecture, the whole base station is situated at the cell tower site. The RRUs are situated at the top of the tower next to the antennas and the BBUs are situated in an hardware room. The RRUs and BBUs are straightforwardly associated through Common Public Radio Interface.