Two-tier PON virtualization with scheduler synchronization supporting application-level ultra-low latency in MEC based cloud-RAN, using MESH-PON

Abstract

Ultra-low end-to-end latency is one of the most important requirements in 5G networks and beyond to support latency-critical applications. Cloud radio access networks and multi-access edge computing (MEC) are considered as the key driving technology that can help reduce end-to-end latency. However, the use of MEC nodes poses radical changes to the access network architecture. As it brings the processing and networking services closer to the edge, it often requires network functions [for example, the centralized unit/distributed unit (CU/DU) stack and application processing] to be distributed across different MEC sites. Therefore, a transport mechanism is needed to efficiently coordinate and connect network functions across MEC nodes. To address this challenge, we propose a two-tier virtualized passive optical network (PON) transport method with scheduler coordination over a virtualized and sliced MESH-PON architecture. While a MESH-PON architecture enables direct communication between MEC nodes hosting CUs/DUs and/or the application processing, our method provides a two-tier virtualized PON transport scheme with coordinated schedulers. This approach greatly reduces latency incurred in transporting signals across the different PON tiers, while maintaining the flexibility of multi-tier methods. We show that our proposed scheme can achieve end-to-end application-level latency below 1 or 2 ms, depending on the network configurations.