Rru optical cable connection

RRU optical cables connect the baseband unit (BBU/DU) to the RRU/AAU using field or hybrid fiber optic cables with specialized connectors for reliable outdoor and indoor deployment.

Types of Optical Cables for RRU

Field Optical Cables: These are lightweight, flexible, and metal-free cables designed for rapid deployment and repeated unplugging in complex environments. They typically come in 1, 2, or 4 cores and are used with removable connector plugs for patch cords or pigtails. Field cables are suitable for outdoor RRU/AAU connections due to their tension resistance, oil resistance, wear resistance, flame retardancy, and wide temperature range . Hybrid Cables (Eucahybrid Boxless): These combine power and fiber optic lines in a compact aluminum corrugated tube. The fiber optic portion connects to the RRU via optical jumper cables, while the power lines connect directly to the RRU. Factory-installed Duplex LC connectors and EucaConnect adaptors ensure robust, IP67/68-rated connections suitable for harsh environments . Remote Optical Cables: Used for local remote extensions, these cables can traverse corridors, pipelines, or across buildings. They are flexible, lightweight, and suitable for both indoor and outdoor use, with high reliability and environmental resistance .

Connection Procedure

1. Antenna End (RRU/AAU): Open the quick-lock fiber optic connector and plug the active connector into the RRU/AAU optical module. Ensure the connector is clean and free of dust to prevent signal loss .

2. Baseband End (BBU/DU): In DRAN mode, the field optical cable is inserted directly into the eCPRI interface on the BBU/DU board. In CRAN mode, it may connect via an ODF unit or a passive wavelength division multiplexer before reaching the BBU/DU .

3. Hybrid Cable Installation: The power cable is connected directly to the RRU, while the fiber optic line uses a jumper cable with EucaConnect adaptors. The adaptors are sealed with dust caps and can be mounted on walls or poles using dedicated brackets .

4. Power and Grounding: For RRUs, power cables are connected to the PDU or DCDU terminals, with shielding layers properly grounded. Ensure waterproofing of cable troughs and unused RF ports .

Best Practices

• Maintain minimum spacing between RRUs to prevent interference and allow maintenance .
• Use IP67/68-rated connectors for outdoor exposure.
• Avoid sharp bends; respect the minimum bending radius of optical cables.
• Ensure clean connectors to minimize insertion loss.
• Verify cable length and attenuation to meet site-specific requirements. By following these guidelines, RRU optical cable connections can achieve reliable, high-performance links between the BBU/DU and RRUs, supporting both 4G and 5G deployments .