Function of bbu optical module

Optical modules on a BBU are critical components that connect the Baseband Unit to the Remote Radio Unit, transmitting high-speed data over optical fibers.Function and RoleOptical modules in a BBU serve as the transmission interface between the BBU and RRU, carrying both bearer data and physical layer information using protocols like CPRI (Common Public Radio Interface) in 4G and eCPRI (Enhanced CPRI) in 5G networks . The BBU is typically located indoors in a temperature-controlled environment, while the RRU is mounted outdoors on telecom towers, making optical modules essential for reliable long-distance data transmission .Types and Specifications4G Networks: Optical modules range from 1.25G SFP to 10G SFP+, with wavelengths around 850nm, operating temperatures of 0–75°C, and transmission distances up to 550m via multimode fiber .5G Networks: Higher-speed modules like 25G SFP28 are used to support eCPRI interfaces, with multimode fiber transmission distances of 70–100m depending on fiber type (OM3 or OM4) and industrial temperature ranges of -40℃ to 85℃ .Industrial Requirements: Optical modules must withstand extreme outdoor temperatures, from -40℃ in cold regions to over 45℃ in hot regions, ensuring stable operation of RRUs .Common IssuesBBU optical modules can experience transmit/receive faults, which may trigger alarms and affect the RF unit operation. Such faults are often linked to power instability or RRU board resets, requiring troubleshooting of both the optical module and connected RRU components .SummaryIn essence, optical modules are the backbone of BBU-RRU communication, enabling high-speed, reliable data transfer in both 4G and 5G networks. Their selection depends on network speed requirements, fiber type, environmental conditions, and protocol compatibility, making them a critical component in modern mobile communication base stations .