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

TL;DR

This work addresses low-latency, tightly synchronized fronthaul for a 7.2 Open RAN split over PON using open hardware and software. It implements a Cooperative Transport Interface that propagates upstream DU grant information to the PON's DBA, embedding these grants in the downlink Bandwidth Map to pre-schedule upstream transmissions within a timeslot of $1\,\mathrm{ms}$. The demonstration uses an open-source stack (srsRAN for DU/CU, Open5GS for core) with Tibit PON hardware and GPS-based synchronization to support dynamic fronthaul bandwidth in the 7.2a split. Results indicate reduced ONU queuing latency and improved QoS under varying fronthaul loads, highlighting the practical viability of open-network CTI for next-generation mobile networks.

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.

Figures (2)

• Figure 1: (a) UE throughput and (b) CTI messages indicating the required bandwidth in the fronthaul.
• Figure 2: Demonstration Physical Architecture