Media use cases for emergency services require mission-critical levels of reliability for the delivery of media-rich services such as video streaming. With the upcoming deployment of the Fifth Generation (5G) networks, a wide variety of applications and services with heterogeneous performance requirements are expected to be supported, and any migration of missioncritical services to 5G networks presents significant challenges in the Quality of Service (QoS), for emergency service operators. This paper presents a novel SliceNet framework, based on advanced and customisable network slicing to address some of the highlighted challenges in migrating eHealth telemedicine services to 5G networks. An overview of the framework outlines the technical approaches in beyond the-state-of-the-art network slicing. Subsequently, the paper emphasises the design and prototyping of a media-centric eHealth use case, focusing on a set of innovative enablers towards achieving end-to-end QoS-aware network slicing capabilities, required by this demanding use case. Experimental results empirically validate the prototyped enablers and demonstrate the applicability of the proposed framework in such media-rich use cases.
In order to effectively keep pace with the global IP traffic growth forecasted in the years to come, Flex-Grid over Multi-Core Fiber (MCF) networks can bring superior spectrum utilization flexibility, as well as bandwidth scalability far beyond the non-linear Shannon's limit. In such a network scenario, however, full node switching reconfigurability will require an enormous node complexity, pushing the limits of current optical device technologies at expenses of prohibitive capital expenditures. Therefore, cost-effective node solutions will most probably be the key enablers of Flex-Grid/MCF networks, at least in the shortand mid-term future. In this context, this paper proposes a cost-effective Reconfigurable Optical Add/Drop Multiplexer (ROADM) architecture for Flex-Grid/MCF networks, called CCC-ROADM, which reduces technological requirements (and associated costs) in exchange of demanding core continuity along the end-to-end communication. To assess the performance of the proposed CCC-ROADM in comparison with a fully-flexible ROADM (i.e., a Fully Non-Blocking ROADM, called FNB-ROADM in this work) in large-scale network scenarios, a novel lightweight heuristic to solve the route, modulation, core and spectrum assignment (RMCSA) problem in Flex-Grid/MCF networks is presented in this work, whose goodness is successfully validated against optimal ILP formulations previously proposed for the same goal. The obtained numerical results in a significant number of representative network topologies with different MCF configurations of 7, 12 and 19 cores show almost identical network performance in terms of maximum network throughput when deploying CCC-ROADMs vs. FNB-ROADMs, while decreasing network capital expenditures to a large extent.
ata centers (DCs) are currently the largest closedloop systems in the information technology (IT) and networking worlds, continuously growing toward multi-million-node clouds [1]. DC operators manage and control converged IT and network infrastructures in order to offer a broad range of services and applications to their customers. Typical services and applications provided by current DCs range from traditional IT resource outsourcing (storage, remote desktop, disaster recovery, etc.) to a plethora of web applications (e.g., browsers, social networks, online gaming). Innovative applications and services are also gaining momentum to the point that they will become main representatives of future DC workloads. Among them, we can find high-performance computing (HPC) and big data applications [2]. HPC encompasses a broad set of computationally intensive scientific applications, aiming to solve highly complex problems in the areas of quantum mechanics, molecular modeling, oil and gas exploration, and so on. Big data applications target the analysis of massive amounts of data collected from people on the Internet to analyze and predict their behavior.All these applications and services require huge data exchanges between servers inside the DC, supported over the DC network (DCN): the intra-DC communication network. The DCN must provide ultra-large capacity to ensure high throughput between servers. Moreover, very low latencies are mandatory, particularly in HPC where parallel computing tasks running concurrently on multiple servers are tightly interrelated. Unfortunately, current multi-tier hierarchical tree-based DCN architectures relying on Ethernet or Infiniband electronic switches suffer from bandwidth bottlenecks, high latencies, manual operation, and poor scalability to meet the expected DC growth forecasts [3].These limitations have mandated a renewed investigation D Abstract Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor flexible enough to efficiently and cost-effectively support highly dynamic application traffic profiles. The FP7 European Project LIGHTNESS foresees extending the capabilities of today's electrical DCNs through the introduction of optical packet switching and optical circuit switching paradigms, realizing together an advanced and highly scalable DCN architecture for ultra-high-bandwidth and low-latency server-to-server interconnection. This article reviews the current DC and high-performance computing (HPC) outlooks, followed by an analysis of the main requirements for future DCs and HPC platforms. As the key contribution of the article, the LIGHTNESS DCN solution is presented, deeply elaborating on the envisioned DCN data plane technologies, as well as on the unified SDN-enabled control plane architectural solution that will empower OPS and OCS transm...
For reliable and efficient network planning and operation, accurate estimation of Quality of Transmission (QoT) before establishing or reconfiguring the connection is necessary. In optical networks, a design margin is generally included in a QoT estimation tool (Qtool) to account for modeling and parameter inaccuracies, ensuring the acceptable performance. In this work, we use monitoring information from an operating network combined with supervised machine learning (ML) techniques to understand the network conditions. In particular, we model the penalties generated due to i.) Erbium Doped Fiber Amplifier (EDFA) gain ripple effect, and ii.) filter spectral shape uncertainties at Reconfigurable Optical Add and Drop Multiplexer (ROADM) nodes. Enhancing the Qtool with the proposed ML regression models yields estimates for new or reconfigured connections that account for these two effects, resulting in more accurate QoT estimation and a reduced design margin. We initially propose two supervised ML regression models, implemented with Support Vector Machine Regression (SVMR), to estimate the individual penalties of the two effects and then a combined model. On Deutsche Telekom (DT) network topology with 12 nodes and 40 bidirectional links, we achieve a design margin reduction of ~1dB for new connection requests.
Abstract-Architectural changes are required at the underlying networks to support the expected Internet data traffic volume growth caused by the popularization of cloud services, 5G-based services, and social networks, whereas providing a highly dynamic connectivity. Cost-effective and energy efficient solutions for flexible network subsystems are required in order to provide future sustainable networks. In this paper, we present a cost-effective DWDM ROADM design enabling optical Metro-Access networks convergence. The cost-effective DWDM ROADM capabilities have been also assessed in an ultra-Dense Wavelength Multiplexing (u-DWDM) Ring Network scenario. In particular, the achievable network throughput has been considered. Index Terms-DWDM; ROADM; Throughput. I. INTRODUCTIONhe ICT eco-system has been rapidly and dramatically changing in the last years. New multimedia and cloud services, the deployment of the Internet of Things (IoT) and the convergence between optical and wireless communications at the 5G paradigm [1] are requiring changes to the networks in order to enable scalable growth in traffic volume, while supporting a high level of dynamic connectivity, full flexibility and increased energy-efficiency. These features can be achieved by considering the cooperation between the network control and data planes. On the one hand, the management and control of networks are evolving towards a Software Defined Networking (SDN)-based centralized architecture (see Fig. 1 accomplished by the subdivision of a DWDM channel into smaller channels called frequency slots (FS) wherein the uplink (U) and the down-link (D) for each user can be established (see Fig. 1). This paper is divided into five sections. Section II presents the proposed cost-effective DWDM Reconfigurable Optical Add-Drop Multiplexer (ROADM) node design, its operation modes and the main advantages of the proposed ROADM architecture. Section III presents the insertion loss, sensitivity and crosstalk measurements and their experimental set-up used for the ROADM characterization. Section IV presents the considered u-DWDM network scenario for proving the cost-effective DWDM ROADM capabilities; an iterative process to design each costeffective DWDM ROADM is proposed in order to obtain the achievable network throughput.Finally, Section V completes the paper with the main conclusions. II. DWDM ROADM NODE ARCHITECTUREThe ROADM design for future Metro-Access converged Networks is basically driven by new network-level requirements, such as full flexibility, adaptability, scalability, resilience and increased energy-efficiency [5]. In order to reach all those features, a new cost-effective
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