The optical module used in the 4G main control board

4G main control boards typically use 1.25G, 2.5G, 6G, or 10G optical modules to connect the BBU and RRU via optical fiber.Role of Optical ModulesIn a 4G base station, the main control board is part of the BBU (Baseband Unit), which processes signals and interfaces with the RRU (Remote Radio Unit). Optical modules are used to convert electrical signals from the BBU into optical signals for transmission over fiber to the RRU, and vice versa for uplink signals. This allows high-speed, long-distance communication between the BBU and RRU while minimizing signal loss and interference .Types of Optical ModulesThe optical modules commonly used in 4G networks include:1.25G optical modules – suitable for lower data rate connections between BBU and RRU.2.5G optical modules – support moderate data rates for standard 4G deployments.6G and 10G optical modules – used in high-capacity or long-distance links, often in dense urban networks . For efficient fiber usage, CWDM (Coarse Wavelength Division Multiplexing) optical modules are often deployed. These modules allow multiple signals to share a single fiber by using different wavelengths, reducing the number of fibers required between BBU and RRU .Optical Module PCBThe optical module itself is mounted on a specialized PCB, often made from high-quality materials like Shengyi S1000-2M, with gold-plated surfaces to ensure signal integrity. These PCBs are designed for high-frequency, high-speed optical communication applications .SummaryIn summary, the 4G main control board relies on optical modules to connect the BBU and RRU efficiently. The choice of module (1.25G, 2.5G, 6G, or 10G) depends on the required data rate and distance. CWDM optical modules are commonly used to optimize fiber usage, and the optical module PCB ensures reliable high-speed signal transmission .