The advent of 5G promises to unleash highly pervasive network coverage and density, increased data rate and capacity, optimized instantiation of virtualized resources in a multi-tenant and multi-service network capable of fulfilling the stringent requirements of various heterogeneous applications. Network slicing is a key enabler of 5G to allow multiple customized and isolated virtual networks upon a single shared physical network infrastructure. In this work, we present a survey of how various network virtualization solutions address slicing, we review the management and orchestration tools available to implement it, and we describe the slicing-aware orchestration platform that we designed for our project (5GCity). Our solution embraces creation of slices of various network elements such as compute nodes, physical networks, radio parts and network edge resources by coordinating different underlying controllers. The platform is being evaluated in three live city pilots (Barcelona, Lucca, and Bristol), already achieving slice creation in a few seconds and control plane latency of a few milliseconds.

Along with the adoption of 5G, the development of neutral host solutions provides a unique opportunity for mobile networks operators to accommodate the needs of emerging use-cases and in the consolidation of new business models. By exploiting the concept of network slicing, as one key enabler in the transition to 5G, infrastructure and service providers can logically split a shared physical network into multiple isolated and customized networks to flexibly address the specific demands of those tenant slices. Motivated by this reality, the H2020 5GCity project proposed a novel 5G-enabled neutral host framework for three European cities: Barcelona (ESP), Bristol (UK), and Lucca (IT). This article revises the main achievements and contributions of the 5GCity project, focusing on the deployment and validation of the proposed framework. The developed neutral host framework encompasses two main parts: the infrastructure and the software platform. A detailed description of the framework implementation, in terms of functional capabilities and practical implications of city-wide deployments, is provided in this article. This work also presents the performance evaluation of the proposed solution during the implementation of real vertical use cases. Obtained results validate the feasibility of the neutral host model and the proposed framework to be deployed in city-wide 5G infrastructures.

Network Function Virtualization (NFV) framework can increase the flexibility and reduce the cost of network functions deployment and operation, but needs to be tailored when this framework is pushed to the domain of edge computing, which is the typical scenario for a 5G neutral host. In such scenario, edge-heavy NFV systems need to address the pressing requirements that comes into play with regard to infrastructure management and multi-layer orchestration, which are typical in a Multi-access Edge Computing (MEC) framework. The European Telecommunications Standards Institute (ETSI) itself has identified a lot of open issues when trying to merge the orchestration life-cycles of NFV and MEC. In this paper we describe a solution that combines extensions in the orchestration and Virtual Infrastructure Management (VIM) layers, along with concrete solutions to the ETSI-identified open issues for NFV-MEC integration, in order to pave the way towards edge-aware NFV solutions for 5G neutral hosts.

The rapid deployment of passive optical access networks (PONs) increases the global energy consumption of networking infrastructure. This paper focuses on the minimization of energy consumption in Ethernet PONs (EPONs). We present an energy-efficient, distributed dynamic bandwidth allocation (DBA) algorithm able to power off the transmitter and receiver of an optical network unit (ONU) when there is no upstream or downstream traffic. Our main contribution is combining the advantages of a distributed DBA (namely, a smaller packet delay compared to centralized DBAs, due to less time being needed to allocate the transmission slot) with energy saving features (that come at a price of longer delays due to the longer queue waiting times when transmitters are switched off). The proposed algorithm analyzes the queue size of the ONUs in order to switch them to doze/sleep mode when there is no upstream/downstream traffic in the network, respectively. Our results show that we minimized the ONU energy consumption across a wide range of network loads while keeping delay bounded.

The rapid adoption of cutting edge media services such as ultra-high definition (UHD/4K) video and immersive media i.e, virtual and augmented reality (VR/AR), will demand large investments in a scalable, ubiquitous, and robust communication infrastructure and services. The H2020 5GCity project aims to solve such issues and beyond while designing, developing, and deploying a sliceable, distributed cloud & edge and radio 5G-platform with neutral hosting capability to support the sharing between information technology (IT) infrastructure owners and media service providers i.e., vertical media actors. In this paper we discuss how 5G technology will facilitate the rise of highly demanding media use cases and its implication on how service providers typically operate (in terms of business model). After a brief introduction of the 5GCity's architecture we present how three media-related use cases will be deployed in the cities of Barcelona, Bristol and Lucca by considering the project's architecture and the underlying neutral host parading to understand the benefits of such model for infrastructure owners and media service providers.