Enabling Multicasting Supports for O-RAN Virtual Function Deployment in Multi-Cloud Environment

Abstract

The proliferation of multi-user applications in next-generation cellular networks sparks the need to simultaneously deploy multicast trees and provisioning services to provide efficient communication. Such a feature allows taking full advantage of the high flexibility of the Open Radio Access Networks (O-RAN) architecture and its open standards, virtualization, and multi-cloud deployment. Enabling multicasting supports in O-RAN, such as 3GPP’s 5G Multicast Broadcast Service capabilities, will unlock and improve a multitude of new O-RAN use cases. Unfortunately, such integration has not yet been clearly defined in O-RAN specifications or fully investigated in prior studies. In this paper, we jointly formulate the Multicast Service Function Chain Embedding (MSE) and O-RAN functional split optimization problems in a multi-cloud environment as an Integer Linear Programming (ILP) model. We address both single and multiple flow request scenarios and propose a Pseudo Knapsack-based heuristic algorithm with polynomial-time complexity, combining feasible search optimization and dynamic programming techniques. Experimental results show that our approach outperforms state-of-the-art baselines, approximating the optimal solution while significantly reducing computational time.