South Korea's mobile service provider LG Uplus and Huawei will deploy WDM/OTN technology for common public radio interface (CPRI) backhaul on LG UpLus's LTE-Advanced network. The CPRI-over-WDM/OTN (Wavelength-Division Multiplexing / Optical Transport Network) solution enables pooled baseband processing for distributed base stations, saving fiber resources and improving network reliability. The solution is a typical application of the "WDM/OTN-to-the-edge" idea in LTE backhaul scenarios.

LG Uplus is adopting pooled baseband processing for distributed base stations on its LTE-A network, to maximize bandwidth and spectrum efficiency, minimize interference caused by coverage overlap, and occupy less footprint. It is estimated that a centralized baseband processing pool in dense metropolitan areas should connect to over 100 remote radio units (RRUs). Traditionally, the RRUs are directly connected to the pool using fibers. This requires considerable fiber resources and does not allow service protection configurations.

According to Huawei, only a single fiber pair is required to backhaul multiple CPRIs from RRUs to the baseband processing pool, greatly saving fiber resources. OTN ring protection for the CPRIs, which is based on unique delay compensation technology, greatly enhances network reliability. Additionally, OTN allows for accurate line performance monitoring and fault diagnosis.