Overview:
One of the major challenges to the adoption of open RAN for 5G networks deployed in dense, urban environments is its sub-optimal support for massive MIMO radios. While there are several reasons behind this performance deficit, a key reason is that the current O-RAN Alliance 7.2x open fronthaul was not originally designed to accommodate massive MIMO radio systems. Recently, the O-RAN Alliance announced a new alternative fronthaul interface specification for use with massive MIMO radio systems.
This Technology Report provides an objective analysis of the O-RAN Alliance’s Next Generation Lower-Layer Split (LLS) and discusses the implications of the new interface on the adoption of open RAN massive MIMO radios.
Table of Contents
- Snapshot
 - Key Takeaways
 - Introduction
 - Overview of Fronthaul Splits
 - The Split 7.2x vs Split 7.3 (or &7.2c) Debate
 - Next Generation Lower-Layer Split (NG-LLS)
- Overview of ULPI Class B and Class A
 - WBDF vs ULPI
- Beamforming
 - Equalisation
 
 - ULPI: Class B vs Class A
 - ULPI: Performance Gains vs Increased RU Complexity
 - Benefits of Equaliser in DU
 - Leveraging AI for Channel Estimation
 - Non-massive MIMO Use Cases
 
 - Implications for 5G RAN Ecosystem
 - Analyst Viewpoint
 
Number of Pages: 14
Publication Date: September 2023