The BBU3900 is a high-performance baseband processing unit that improves signal stability, processing speed, and power efficiency in fiber optic systems, offering better compatibility and performance compared to the WD2BBUC. About This Document About This Document Introduction This document describes the BBU3900 hardware, such as boards, module, ports, cables, and connectors, and the functions of the hardware. Product Version The following table lists the product versions related to this document. • Only when the BBU install in TP48200A and APM30H cabinets, subrack cable claws are configured. Preferentially configured in S19.