RT Journal Article T1 Optimal Deployment Framework for Multi-Cloud Virtualized Radio Access Networks A1 Murti, Fahri Wisnu A1 Ayala Romero, José A. A1 García Saavedra, Andrés A1 Costa-Pérez, Xavier A1 Iosifidis, George AB Virtualized radio access networks (vRAN) are emerging as a key component of wireless cellular networks, and it is therefore imperative to optimize their architecture. vRANs are decentralized systems where the Base Station (BS) functions can be split between the edge Distributed Units (DUs) and Cloud computing Units (CUs); hence they have many degrees of design freedom. We propose a framework for optimizing the number and location of CUs, the function split for each BS, and the association and routing for each DU-CU pair. We combine a linearization technique with a cutting-planes method to expedite the exact problem solution. The goal is to minimize the network costs and balance them with the criterion of centralization, i.e., the number of functions placed at CUs. Using data-driven simulations we find that multi-CU vRANs achieve cost savings up to 28% and improve centralization by 77%, compared to single-CU vRANs. Interestingly, we see non-trivial trade-offs among centralization and cost, which can be aligned or conflicting based on the traffic and network parameters. Our work sheds light on the vRAN design problem from a new angle, highlights the importance of deploying multiple CUs, and offers a rigorous optimization tool for balancing costs and performance. PB IEEE SN 1536-1276 YR 2020 FD 2020-12-09 LK https://hdl.handle.net/10016/31829 UL https://hdl.handle.net/10016/31829 LA eng NO In Press / En prensa NO This work was supported by Science Foundation Ireland (SFI) under Grant No. 17/CDA/4760. This work has been partially supported by EC H2020 5GPPP 5Growth project (Grant 856709). This publication has emanated from research supported in part by a research grant from SFI and is co-funded under the European Regional Development Fund under Grant Number 13/RC/2077. DS e-Archivo RD 27 jul. 2024