C-RAN architecture can reduce the number of equipment rooms and enable BBU resource sharing and collaboration.
Therefore, compared with the D-RAN mode of 4G, the C-RAN mode is gaining more importance, and so is the fronthaul solution.
Fronthaul is to enable better transmission between AAUs and BBUs in the C-RAN architecture.
Thanks to its mature industry chain, power-free design, and plug-and-play features, the passive CWDM fronthaul solution has been commercially used in a large scale. However, it still has many deficiencies in the following aspects:
- Environment: When the ambient temperature is higher than 35°C, the transmit optical power of the optical module is unstable and wavelength drift may occur. In severe cases, services may be transiently interrupted.
- Reliability: In the 4G era, most services are individual services, and service interruption has a small impact. In the 5G era, new services emerge, such as unmanned driving and industrial manufacturing. Service interruption has a great impact and highly reliable networks are required.
- O&M: The number of wireless sites keeps increasing, resulting in the increase of fronthaul networks. These networks need to be effectively managed and maintained to reduce O&M costs.
