In this paper, network function virtualization (NFV) is identified as a promising key technology, which can contribute to energy-efficiency improvement in 5G networks. An optical network supported architecture is proposed and investigated in this paper to provide the wired infrastructure needed in 5G networks and to support NFV toward an energy efficient 5G network. In this paper, the mobile core network functions, as well as baseband function, are virtualized and provided as VMs. The impact of the total number of active users in the network, backhaul/fronthaul configurations, and VM inter-traffic are investigated. A mixed integer linear programming (MILP) optimization model is developed with the objective of minimizing the total power consumption by optimizing the VMs location and VMs servers' utilization. The MILP model results show that virtualization can result in up to 38% (average 34%) energy saving. The results also reveal how the total number of active users affects the baseband virtual machines (BBUVMs) optimal distribution whilst the core network virtual machines (CNVMs) distribution is affected mainly by the inter-traffic between the VMs. For real-time implementation, two heuristics are developed, an energy efficient NFV without CNVMs inter-traffic (EENFVnoITr) heuristic and an energy efficient NFV with CNVMs inter-traffic (EENFVwithITr) heuristic, both produce comparable results to the optimal MILP results. Finally, a genetic algorithm is developed for further verification of the results.

A Number of merits could be brought by network function virtualization (NFV) such as scalability, on demand allocation of resources, and the efficient utilization of network resources. In this paper, we introduce a framework for designing an energy efficient architecture for 5G mobile network function virtualization. In the proposed architecture, the main functionalities of the mobile core network which include the packet gateway (P-GW), serving gateway (S-GW), mobility management entity (MME), policy control and charging role function, and the home subscriber server (HSS) functions are virtualized and provisioned on demand. We also virtualize the functions of the base band unit (BBU) of the evolved node B (eNB) and offload them from the mobile radio side. We leverage the capabilities of gigabit passive optical networks (GPON) as the radio access technology to connect the remote radio head (RRH) to new virtualized BBUs. We consider the IP/WDM backbone network and the GPON based access network as the hosts of virtual machines (VMs) where network functions will be implemented. Two cases were investigated; in the first case, we considered virtualization in the IP/WDM network only (since the core network is typically the location that supports virtualization) and in the second case we considered virtualization in both the IP/WDM and GPON access network. Our results indicate that we can achieve energy savings of 22% on average with virtualization in both the IP/WDM network and GPON access network compared to the case where virtualization is only done in the IP/WDM network. INTRODUCTIONThe current mobile system has evolved from circuit-switched based analogue voice network to a formidable system supporting hundreds of thousands of various applications and a very huge number of users. We are just at the dawn of the conversion to ubiquitous high data rate network that connects anything to anything anytime and anywhere. Therefore, the next generation mobile network will not only connect people, but anything that needs the use of its resources. Various devices will join this network such as medical devices, meteorological equipment, traffic and security cameras, household appliances, etc. As a result, the next generation mobile network will affect many spheres of human life and the growth in traffic will continue during the 5G era beyond 2020 [1,2]. Mobile operators and service providers will have to deal with a 1000 fold increase in traffic compared to the levels in 2010 [3] and they have to properly address a number of challenges due to this huge amount of traffic such as bandwidth requirements and power consumption. In order to address the power consumption challenges, in [4] we have proposed an energy efficient virtual network embedding (EEVNE) approach for cloud computing networks. In [5] we have introduced a framework for energy efficient cloud computing over IP/WDM networks. We have examined energy efficient future HDTV in [6] and investigated the role of physical topology optimization on energy efficiency ...

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Passive optical networks (PON) technology is increasingly becoming an attractive solution in modern data centres as it provides energy efficient, high capacity, low cost, scalable and flexible connectivity. In this paper we report the implementation of a PON based data centre architecture that provides high resilience and high speed interconnections by providing alternative communication routes between servers in different racks. Each rack is divided into several groups of servers and connects to other racks and the Optical Line Terminal (OLT) through a set of server that acts as relay servers. We implement the switching and routing functionalities within servers using 4x10GE Xilinx NetFPGA, and demonstrate end-to-end communication using IP cameras live video streaming over up to 100 km optical connections through WDM nodes and the PON network.

Fog radio access network (F-RAN) and virtualisation are promising technologies for 5G networks. In F-RAN, the fog and cloud computing are integrated where the conventional C-RAN functions are diverged to the edge devices of radio access networks. F-RAN is adopted to mitigate the burden of front-haul and improve the end to end (E2E) latency. On other hand, virtualization and network function virtualization (NFV) are IT techniques that aim to convert the functions from hardware to software based functions. Many merits could be brought by the employment of NFV in mobile networks including a high degree of reliability, flexibility and energy efficiency. In this paper, a virtualization framework is introduced for F-RAN to improve the energy efficiency in 5G networks. In this framework, a gigabit passive optical network (GPON) is leveraged as a backbone network for the proposed F-RAN architecture where it connects several evolved nodes B (eNodeBs) via fibre cables. The energy-efficiency of the proposed F-RAN architecture has been investigated and compared with the conventional C-RAN architecture in two different scenarios using mixed integer linear programming (MILP) models. The MILP results indicate that on average a 30% power saving can be achieved by the F-RAN architecture compared with the C-RAN architecture. INTRODUCTIONIn 1947, the architecture and concept of cellular communications were proposed for the first time by the American Telephone & Telegraph (AT&T) company [1]. Since then, wireless communication systems have experienced several significant evolutions, achieving transformations from a simplex analogue voice network to a heterogeneous and efficient communication system. The current mobile generation namely "4G" supports many applications and a huge number of users. In the last ten years, with the development of information technology, the advent of new mobile technologies such as high resolution video and Internet of Things (IoT) have transformed wireless communication systems form a network that connects people, to a network of anything at anytime and anywhere [2] - [6]. The rapid growth in the number of connected devices and the rise in the variety and data needs of applications has resulted in an explosive traffic growth in the network and harsh E2E requirements [7]. Therefore, the traffic volume in the next generation of mobile networks (5G) is expected to increase by a factor of 1000 compared to current mobile communication systems [8] -[12] while the latency and other requirements comprehensively transcend the capabilities of 4G communication systems [13] - [15]. C-RAN and NFV were studied as potential 5G solutions which can achieve the target of reducing signal interference at the edge of cellular networks, and support adaptive spectrum slicing and sharing via centralized management and coordination between eNodeBs [16], [17]. In C-RAN and NFV deployments, the function of the base band unit (BBU) can be separated from eNodeBs and can be virtualized to construct BBU pools in the access network (su...