Introduction
With the full-scale deployment of 5G networks, the fronthaul network connecting AAUs (Active Antenna Units) and DUs (Distributed Units) demands massive quantities of optical modules. 25G optical modules have become the mainstream choice for 5G fronthaul due to their optimal balance of bandwidth and cost.
This article provides a comprehensive comparison of various 25G SFP28 optical module types, helping you make the best selection for your 5G fronthaul network.
5G Fronthaul Network Architecture
5G fronthaul networks primarily use the eCPRI protocol, compressing CPRI data between AAU and DU for transmission over 25G interfaces. Typical fronthaul distances range from 1-20 km, covering outdoor macro base stations, indoor distribution systems, and small cells.
25G SFP28 Optical Module Type Comparison
25G SFP28 SR (Short Reach): 850nm VCSEL, 300m over OM4 fiber, ideal for intra-data center connections.
25G SFP28 LR (Long Reach): 1310nm DFB, 10km over single-mode fiber, the most common type for 5G fronthaul.
25G SFP28 ER (Extended Reach): 1310nm EML, 30-40km, suitable for longer fronthaul distances.
25G SFP28 BiDi (Bi-Directional): 1270nm/1330nm, 10-20km on single fiber, saves 50% fiber resources.
25G SFP28 CWDM: 1271-1371nm channels, works with CWDM multiplexers for multi-channel single-fiber transmission.
Key Selection Parameters
Distance: Choose LR for under 10km, ER/ER+Lite for 10-30km.
Fiber Resources: BiDi modules save 50% fiber — ideal for fiber-scarce scenarios.
WDM Solutions: CWDM/MWDM modules with passive multiplexers for multi-site fiber sharing.
Power Consumption: 5G fronthaul requires <1.5W, industrial temperature range (-40°C to 85°C).
DDM Diagnostics: Digital Diagnostic Monitoring for real-time optical power, temperature, and voltage.
Compatibility: MSA standard SFP28 form factor ensures compatibility with base station and transmission equipment.
Operator Solutions Comparison
China Mobile: MWDM solution with tighter wavelength accuracy, supporting 12 channels.
China Telecom: LWDM based on LAN-WDM technology, also 12 wavelengths.
China Unicom: DWDM solution supporting 40+ wavelengths for future capacity expansion.
While each operator has a preferred approach, CWDM and BiDi remain the most widely deployed solutions today.
Buying Recommendations
1. Standard fronthaul (1-10km) → 25G SFP28 LR, best cost-performance ratio
2. Limited fiber resources → 25G SFP28 BiDi, saves 50% fiber
3. Extended distance (10-30km) → 25G SFP28 ER or ER+Lite
4. Multi-site fiber sharing → CWDM 6-wave or 12-wave solution
5. Indoor/short-reach → 25G SFP28 SR (100m-300m)
6. Always choose industrial temperature range (-40°C to 85°C) modules
Conclusion
25G SFP28 optical modules are core components of 5G fronthaul networks. Selection requires comprehensive consideration of distance, fiber resources, WDM solutions, power consumption, and temperature range. LR and BiDi solutions dominate the current market, with CWDM multi-wave solutions also being deployed at scale.
Langzhi Technology offers a full range of 25G SFP28 optical modules including SR, LR, ER, BiDi, and CWDM types, meeting all 5G fronthaul network requirements.
