Optical Front/Mid-haul with Open Access-Edge Server Deployment Framework for Sliced O-RAN

TL;DR

This paper presents a cost-effective optical front/mid-haul framework for O-RAN that optimally places RUs and connects them to edge servers, ensuring diverse QoS for 5G slices.

Contribution

It introduces a novel framework using TWDM-PON for RU placement and server deployment, with formulated optimization and heuristics for efficient network slicing.

Findings

TWDM-PON-based framework reduces deployment costs.

Framework satisfies diverse QoS for different 5G slices.

Outperforms OTN-based solutions in various deployment scenarios.

Abstract

The fifth-generation of mobile radio technologies is expected to be agile, flexible, and scalable while provisioning ultra-reliable and low-latency communication (uRLLC), enhanced mobile broadband (eMBB), and massive machine type communication (mMTC) applications. An efficient way of implementing these is by adopting cloudification, network function virtualization, and network slicing techniques with open-radio access network (O-RAN) architecture where the base-band processing functions are disaggregated into virtualized radio unit (RU), distributed unit (DU), and centralized unit (CU) over front/mid-haul interfaces. However, cost-efficient solutions are required for designing front/mid-haul interfaces and time-wavelength division multiplexed (TWDM) passive optical network (PON) appears as a potential candidate. Therefore, in this paper, we propose a framework for the optimal placement of RUs based on long-term network statistics and connecting them to open access-edge servers for hosting the corresponding DUs and CUs over front/mid-haul interfaces while satisfying the diverse QoS requirements of uRLLC, eMBB, and mMTC slices. In turn, we formulate a two-stage integer programming problem and time-efficient heuristics for users to RU association and flexible deployment of the corresponding DUs and CUs. We evaluate the O-RAN deployment cost and latency requirements with our TWDM-PON-based framework against urban, rural, and industrial areas and show its efficiency over the optical transport network (OTN)-based framework.