Software‐Defined Optical Networking (SDON): Principles and Applications

Featured by the advantages of high capacity, long transmission distance, and low energy consumption, optical network has been deployed widely as the most important infrastructure for backbone transport network. With the development of Internet, datacenter has become the popular infrastructure for cloud computing, which needs to be connected with high bitrate transport network to support heterogeneous applications. In this case, optical network also becomes a promising option for intra and inter‐datacenter networking. In the networking field, software‐defined networking (SDN) has gained a lot of attention from both academic and industry, and it aims to provide a flexible and programmable control plane. SDN is applicable to optical network, and the optical network integrated with SDN, namely software‐defined optical network (SDON), are expected as the future transport solutions, which can provide both high bitrate connectivity and flexible network applications. The principles and applications of SDON are introduced in this chapter

Resource orchestration strategies with retrials for latency-sensitive network slicing over distributed telco clouds

The new radio technologies (i.e. 5G and beyond) will allow a new generation of innovative services operated by vertical industries (e.g. robotic cloud, autonomous vehicles, etc.) with more stringent QoS requirements, especially in terms of end-to-end latency. Other technological changes, such as Network Function Virtualization (NFV) and Software-Defined Networking (SDN), will bring unique service capabilities to networks by enabling flexible network slicing that can be tailored to the needs of vertical services. However, effective orchestration strategies need to be put in place to offer latency minimization while also maximizing resource utilization for telco providers to address vertical requirements and increase their revenue. Looking at this objective, this paper addresses a latency-sensitive orchestration problem by proposing different strategies for the coordinated selection of virtual resources (network, computational, and storage resources) in distributed DCs while meeting vertical requirements (e.g., bandwidth demand) for network slicing. Three orchestration strategies are presented to minimize latency or the blocking probability through effective resource utilization. To further reduce the slice request blocking, orchestration strategies also encompass a retrial mechanism applied to rejected slice requests. Regarding latency, two components were considered, namely processing and network latency. An extensive set of simulations was carried out over a wide and composite telco cloud infrastructure in which different types of data centers coexist characterized by a different network location, size, and processing capacity. The results compare the behavior of the strategies in addressing latency minimization and service request fulfillment, also considering the impact of the retrial mechanism.This work was supported in part by the Department of Excellence in Robotics and Artificial Intelligence by Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) to Scuola Superiore Sant’Anna, and in part by the Project 5GROWTH under Agreement 856709

Software Defined Applications in Cellular and Optical Networks

abstract: Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. A novel access backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Based on software defined networking (SDN) a management mechanism that allows multiple operator to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells has been proposed. This dissertation also comprehensively survey the studies that examine the SDN paradigm in optical networks. Along with the PHY functional split improvements, the performance of Distributed Converged Cable Access Platform (DCCAP) in the cable architectures especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In the PHY functional split, in addition to the re-use of infrastructure with a common FFT module for multiple technologies, a novel cross functional split interaction to cache the repetitive QAM symbols across time at the remote node to reduce the transmission rate requirement of the fronthaul link has been proposed.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Network Virtualization Over Elastic Optical Networks: A Survey of Allocation Algorithms

Network virtualization has emerged as a paradigm for cloud computing services by providing key functionalities such as abstraction of network resources kept hidden to the cloud service user, isolation of different cloud computing applications, flexibility in terms of resources granularity, and on‐demand setup/teardown of service. In parallel, flex‐grid (also known as elastic) optical networks have become an alternative to deal with the constant traffic growth. These advances have triggered research on network virtualization over flex‐grid optical networks. Effort has been focused on the design of flexible and virtualized devices, on the definition of network architectures and on virtual network allocation algorithms. In this chapter, a survey on the virtual network allocation algorithms over flexible‐grid networks is presented. Proposals are classified according to a taxonomy made of three main categories: performance metrics, operation conditions and the type of service offered to users. Based on such classification, this work also identifies open research areas as multi‐objective optimization approaches, distributed architectures, meta‐heuristics, reconfiguration and protection mechanisms for virtual networks over elastic optical networks

Latency-aware resource orchestration in SDN-based packet over optical flexi-grid transport networks

In the upcoming 5G networks and following the emerging Software Defined Network/Network Function Virtualization (SDN/NFV) paradigm, demanded services will be composed of a number of virtual network functions that may be spread across the whole transport infrastructure and allocated in distributed Data Centers (DCs). These services will impose stringent requirements such as bandwidth and end-to-end latency that the transport network will need to fulfill. In this paper, we present an orchestration system devised to select and allocate virtual resources in distributed DCs connected through a multi-layer (Packet over flexi-grid optical) network. Three different on-line orchestration algorithms are conceived to accommodate the incoming requests by satisfying computing, bandwidth and end-to-end latency constraints, setting up multi-layer connections. We addressed end-to-end latency requirements by considering both network (due to propagation delay) and processing delay components. The proposed algorithms have been extensively evaluated and assessed (via a number of figures of merit) through experimental tests carried out in a Packet over Optical Flexi-Grid Network available in the ADRENALINE testbed with emulated DCs connected to it.This work has been partially funded by the EC H2020 5GTransformer Project (grant No. 761536)

Eficiência energética em redes ópticas elásticas

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2021.Com o crescimento da Internet e o advento das aplicações emergentes, o consumo energético das redes de núcleo vem ganhando maior destaque na academia e na indústria. O surgimento das Redes Ópticas Elásticas (Elastic Optical Networks – EON) trouxe novas concepções nas operações das redes de núcleo, melhorando sua flexibilidade e eficiência no uso dos recursos. Suas características proporcionam uma maior versatilidade e escalabilidade na alocação do espectro. Tendo em vista que o consumo energético é um fator que está ganhando relevância especial no planejamento e na operação das redes de núcleo, esta Tese dedica-se ao estudo da eficiência energética nas EONs apresentando suas características, modelo de consumo energético e as principais linhas de pesquisa encontradas na literatura sobre eficiência energética em EON. Para isso, propõem-se três estudos que abordam diferentes aspectos relativos à eficiência energética em EON. O primeiro estudo, apresenta uma solução para o problema de roteamento e alocação de espectro com modulação adaptativa (Routing, Modulation Level, and Spectrum Allocation – RMLSA) em EONs translúcidas. Propõe-se um esquema de modulação adaptativa, acoplável a qualquer algoritmo de alocação de espectro EON, que promove eficiência energética através do uso de níveis de modulação mais eficientes. No segundo estudo, uma nova perspectiva para o problema RMLSA é investigada explorando técnicas de agregação de tráfego elétrica e óptica para EONs. Propõe-se um modelo de programação linear inteira que leva em consideração todas as características da arquitetura EON e técnicas de engenharia de tráfego para resolver o problema RMLSA dinâmico com eficiência energética. Por fim, o último estudo, apresenta um algoritmo heurístico para resolução do problema RMLSA translúcido dinâmico com técnicas de agregação de tráfego. A proposta baseia-se em um modelo de grafo auxiliar que melhora o consumo de energia da rede através de políticas de engenharia de tráfego inovadoras. Os resultados obtidos nos estudos apresentados, garantem uma redução significativa na taxa de bloqueio para diversas soluções RMLSA da literatura sem comprometer a eficiência energética da rede.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).With the growth of the Internet and the arising of emerging applications, the energy consumption of core networks has gained greater relevance in academia and industry. The emergence of Elastic Optical Networks (EON) brought new conceptions in the operations of core networks, improving network flexibility and efficiency in the use of resources. Its features provide greater versatility and scalability in spectrum allocation. Considering that energy consumption is a factor that is gaining special relevance for the planning and operation of core networks, this Thesis is dedicated to the study of the energy efficiency in the EON presenting its main characteristics, energy consumption models, and the main research lines found in the literature on energy efficiency in EON. For this, three studies are proposed that address different aspects related to energy efficiency in EON. The first study presents a solution to Routing, Modulation Level, and Spectrum Allocation (RMLSA) problem in translucent EONs. An adaptive modulation scheme is proposed, which can be connected to any EON spectrum allocation algorithm, which promotes energy efficiency through the use of more efficient modulation levels. In the second study, a new perspective for the RMLSA problem is investigated exploring electrical and optical grooming techniques for EONs. A linear programming model is proposed that takes into account all the characteristics of the EON architecture and traffic engineering techniques to solve the dynamic RMLSA problem with energy efficiency. Finally, the last study presents a heuristic algorithm for solving the dynamic translucent RMLSA problem with traffic grooming techniques. The proposal is based on an auxiliary graph model that improves the energy consumption of the network through innovative traffic engineering policies. The results obtained in the studies presented, guarantee a significant reduction in the blocking rate for several RMLSA solutions of the literature without compromising the energy efficiency of the network