In 4G networks, the optical modules used to connect BBU and RRU are mainly gigabit to 10Gbit optical modules. The BBU is small and exquisite, with low power consumption, while the RRU is large and has. AAU, RRU, and BBU are key components in a telecom network, particularly in modern wireless. The base station can be divided into two modules: the RRU for transmitting signals and the BBU for processing signals. Currently, 5G of the bearer network mainly uses 25Gbps optical. Below is a breakdown of the BBU (Baseband Unit), RRU (Remote Radio Unit), and AAU (Active Antenna Unit)—their roles, placement, connectivity, and relevance in evolving technologies. • Performs baseband processing: encoding.