If the length of the CPRI optical fiber between a BBU and an RRU exceeds...

The Common Public Radio Interface (CPRI) is a standard that defines the interface between the BBU (baseband unit) and the RRU (remote radio unit) in a wireless base station. The BBU and the RRU are connected by an optical fiber cable, known as the CPRI optical fiber.

The CPRI optical fiber is used to transport the digital baseband signals between the BBU and the RRU. The distance between the BBU and the RRU can be up to several kilometers, but the standard CPRI specification only supports a maximum distance of 150m between the BBU and RRU using single-mode fiber. If the distance exceeds 150m, multimode fiber should be used to extend the distance between the BBU and the RRU.