부산대학교 도서관

Dynamic Cloud Radio Access Network (Dynamic C-RAN) is an emerging wireless architecture that aims for flexibility, business agility, adaptability, among other benefits. In a Dynamic C-RAN, wireless functionalities can be split into smaller components and distributed along a hierarchical cloud infrastructure. Network Functions Virtualization (NFV) concepts have been recently investigated to facilitate management-related operations of these wireless functionalities. Despite the many advocated advantages of the function's splitting and the effectiveness of NFV orchestration solutions, both academia and industry are considering Virtualized Network Functions (VNF)s as atomic elements, disregarding the potential advantages of splitting VNFs into several different components. Aiming to improve VNF orchestration in Dynamic C-RAN scenarios, in this paper we propose Maestro: an NFV orchestrator for wireless environments that is able to decide among several possible VNF compositions which are more suitable for each situation. Maestro is designed to operate using different decision mechanisms that can be defined based on network operators' needs. We evaluate the effectiveness of our proposal by modeling the orchestrator's decision mechanism as a linear programming problem. Thus, we show how fronthaul bandwidth consumption can be reduced threefold considering different VNF compositions against atomic VNF placement.