How many optical modules does one RRU use

A typical RRU uses 2 to 6 optical modules to connect with the BBU, depending on network type and data rate requirements.

Optical Modules in 4G RRUs

In 4G networks, RRUs are connected to BBUs using optical modules that support data rates from 1.25G to 10G. Each RRU generally requires 2 to 6 optical fibers to handle uplink and downlink traffic, depending on the number of antennas and MIMO configuration . These optical modules can include SFP or SFP+ types, and in some cases, CWDM (Coarse Wavelength Division Multiplexing) modules are used to reduce fiber usage while supporting multiple channels .

Optical Modules in 5G RRUs

For 5G networks, the optical modules typically support 25G rates to accommodate higher bandwidth and low-latency requirements . The interface between the BBU and RRU often uses CPRI or eCPRI protocols, and multiple optical modules may be deployed to support massive MIMO and multi-band operation . The exact number of modules depends on the RRU design, number of transmit/receive chains, and deployment scenario.

Factors Affecting the Number of Optical Modules

• MIMO Configuration: More antennas require more optical channels.
• Data Rate: Higher throughput RRUs need higher-speed modules or multiple fibers.
• Network Type: 5G RRUs generally require faster modules than 4G RRUs.
• Fiber Resource Optimization: CWDM or WDM solutions can reduce the number of physical fibers while maintaining multiple channels . In summary, one RRU typically contains 2 to 6 optical modules in 4G networks, while 5G RRUs may use multiple 25G modules depending on the number of antennas and required throughput, with the exact number varying by manufacturer and deployment scenario .