CPRI is an open specification for an interface between Radio Equipment Controllers (REC) often referred to as BBU, and Radio Equipment (RE), often referred to as RRH. The use of a CPRI interface run over a single-mode or multi-mode fiber enables the radio equipment to be mounted at the top of a tower very close to the antennas. The BBU and RRH can be up to 2 km apart using single-mode fiber or up to 25 km in a C-RAN network, facilitating the use of BBU hotels. The latest specification version 7.0 supports up to 24 Gbps line rates.

CPRI is of particular interest for mobile operators willing to deploy their networks following the novel cloud radio access network approach. In such a case, CPRI provides an interface for the interconnection of remote radio heads with a baseband unit by means of the so-called fronthaul network.