Aluno: Maicon Kist
Orientador: Prof. Dr. Juergen Rochol
Título: Radio and Baseband Unit Virtualization: Pushing the Boundaries of Future Mobile Networks
Linha de Pesquisa: Redes de Computadores
Local: Prédio 43412 – Sala 215 (sala de videoconferência) do Instituto de Informática
– Prof. Dr. José Ferreira de Rezende (UFRJ – por videoconferência)
– Prof. Dr. Kleber Vieira Cardoso (UFG – por videoconferência)
– Prof. Dr. Edison Pignaton de Freitas (UFRGS)
Presidente da Banca: Prof. Dr. Juergen Rochol
Abstract: Existing mobile networks rely on closed and inflexible hardware-based architectures both at the radio frontend and in the core network. This hardware dependence significantly delays the adoption and deployment of new standards, impose significant challenges in implementing in- novative new radio access technologies to maximize the network capacity and coverage, and prevent provisioning of truly- differentiated services that can adapt to uneven and highly vari- able traffic patterns. Because of such limitations, it is expected that future 5G mobile networks should be constructed based on the baseband centralization architecture. In such an architecture, the computational processing resources are centralized and software-defined implementations replace baseband unit hardwares. Although baseband centralization architecture brings several opportunities for future 5G mobile networks, it is not free from challenges. Among the dif- ferent challenges existent, we highlight the most relevant ones, (i) a single “one-size-fits-all” access technology, (ii) network coverage is limited, and (iii) high bandwidth requirements for fronthaul links. To address these challenges, we push the boundaries of mobile network architectures with the HYpervisor for software-Defined RAdio (HyDRA) and Architecture for fine-grained Baseband Unit viRtualizatioN (ABURN). HyDRA is a radio virtualization layer that enables multiple heterogeneous access technologies to coexist on top of the same radio front-end. It uses innovative baseband processing techniques to slice and abstract a radio front- end into multiple virtual radio front-ends. ABURN integrates HyDRA to realize a flexible and adaptable solution in which each vBBU functionality is moved to a virtualized containers, i.e., fine-grained vBBU. ABURN solves the challenges of current centralized baseband archi- tectures while enabling an unprecedented control over any aspect of the access network. The methodology employed to show the feasibility of our proposal is divided evaluating HyDRA and ABURN. For HyDRA, we developed a prototype which was evaluated in an experimental 5G-like network in which one physical RRH is virtualized into two vRRHs to provide con- nectivity services with vastly different requirements. Our results show that HyDRA is able to multiplex virtual radio front-ends into a single hardware, enabling multiple access technolo- gies tailored for particular services to share the same radio front-end. For ABURN, we have performed mathematical analysis to obtain the fronthaul bandwidth required for different fine- grained vBBU distribution, as well performed simulations to obtain the maximum number of vBBUs that can operate over a constrained fronthaul. Our results for ABURN show that fine- grained vBBU adds the flexibility and scalability that is required in future 5G mobile networks. HyDRA and ABURN push the boundaries of future mobile networks by adding an unforeseen level of programmability, flexibility, and scalability, while also catalyzing innovations in a range of areas, from the introduction of new access technologies specialized in specific services, to the management of data center and fronthaul resources.
Keywords: Software defined radio. virtualization. baseband signal processing. functional split. 5G. network function virtualization.