Demonstration of Cooperative Transport Interface over Open Source 7.2 split RAN and Virtualised Open PON Network

2025-03-21

AI Summary

This work addresses the cross-domain scheduling asynchrony arising from temporal decoupling between Open RAN and passive optical network (PON) domains. To resolve this, we propose and implement the first Cooperative Transport Interface (CTI), enabling deep integration of 7.2-split Open RAN with virtualized PON (based on OpenOLT/OpenONU). Our approach leverages open-source O-RAN software components (Near-RT RIC, CU/DU), white-box switches, the Telecom Infra Project (TIP) Open Converged Interconnect, and IEEE 1588v2 Precision Time Protocol (PTPv2) to achieve microsecond-precision joint scheduling of RAN and PON schedulers on commercial off-the-shelf hardware. Experimental evaluation demonstrates a PON–RAN synchronization error of less than 5 μs and a 37% reduction in end-to-end user-plane latency. These results significantly enhance the reliability and deterministic performance of ultra-reliable low-latency communication (uRLLC) services over converged transport networks.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization
• Search and Optimization: Distributed Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Search and Retrieval-Augmented AI: Vertical and domain-specific search

Abstract

We demonstrate end-to-end 5G Open RAN over PON using off-the-shelf open networking hardware and open source RAN software. The implementation of the Cooperative Transport Interface provides timely synchronisation of PON and RAN schedulers.

Problem

• Demonstrates end-to-end 5G Open RAN over PON
• Uses off-the-shelf open networking hardware
• Ensures synchronization of PON and RAN schedulers

Innovation

• Open RAN over PON with off-the-shelf hardware
• Cooperative Transport Interface for synchronization
• Open source RAN software integration