Salvatore Spadaro

Salvatore Spadaro
Universitat Politècnica de Catalunya | UPC · Department of Signal Theory and Communications (TSC)

Professor

About

171
Publications
14,530
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1,176
Citations

Publications

Publications (171)
Article
In order to compete for a prominent market share, network operators and service providers should retain and increase the verticals’ subscription, catering to their needs in order to differentiate themselves from competitors. In this scenario, verticals’ satisfaction arises of paramount importance. As such, user experience is becoming a reliable ind...
Article
Full-text available
Leaving the current 4th generation of mobile communications behind, 5G will represent a disruptive paradigm shift integrating 5G Radio Access Networks (RANs), ultra-high-capacity access/metro/core optical networks, and intra-datacentre (DC) network and computational resources into a single converged 5G network infrastructure. The present paper over...
Article
Full-text available
For reliable and efficient network planning and operation, accurate estimation of Quality of Transmission (QoT) is necessary. In optical networks, a physical layer model (PLM) is typically used as a QoT estimation tool (Qtool) including a design margin to account for modeling and parameter inaccuracies, to ensure acceptable performance. Such margin...
Article
Having ubiquitous optical monitors in dense wavelength-division multiplexing (DWDM) or flex-grid networks allows the estimation in real time of crucial parameters. Such monitoring would be even more important in disaggregated optical networks, to inspect performance issues related to inter-vendor interoperability. Several important parameters can b...
Conference Paper
We present an architectural solution based on data analytics for self-organizing optical data centers. Thanks to a reinforcement learning-based cognitive layer, an adaptive and autonomous resource assignment to deployed services is achieved.
Article
Full-text available
Network Slicing appears as one of the enabling technologies for 5G networks to accommodate services with different requirements and availability. The present work seizes the use of network slicing and focuses on the deployment and maintenance of services which are sensitive to latency constraints. For this purpose, the design and use of a VNF laten...
Article
Network architectural changes to satisfy all the 5G+ mobile network specifications and requirements are necessary due to the popularization of streaming and cloud applications on omnipresent portable devices. The combination of massive installation of micro-cell antenna sites with the cloud access radio network (C-RAN) architecture has recently bee...
Article
Full-text available
In this paper, we focus on the design of different node architectures suitable for Few-Mode Multi-Core Fibers (FM-MCFs) based networks. Both dimensions, core and mode, open different possible ways to group spatial channels depending on the physical impairments of the Space-Division Multiplexed (SDM) optical fibers. Moreover, the channel switching a...
Article
Today's optical transport networks are complex already and the support of the new arising services will further increase such complexity. Traditional deterministic network procedures will need to be revisited, especially their operations. Network Operators will require more dynamic approaches to get the best out of their infrastructure. In this con...
Conference Paper
In this paper, we motivate a brown-field migration planning as a cost-efficient procedure to scale the capacity of short-term realizable elastic optical networks (EONs), gradually converting them into spectrally-spatially flexible optical networks (SS-FONs). After a formal statement of the brown-field EON to SS-FON migration planning problem, a Sto...
Article
The ever-growing data traffic volume inside data centers caused by the popularization of cloud services and edge computing demands scalable and cost-efficient network infrastructures. With this premise, optical interconnects have recently gained more and more research attention as a key building block to ensure end-to-end energy efficient solutions...
Article
We report experimental results of a semiconductor optical amplifier (SOA) for optical amplification in a 50-90 Gb/s IM-DD optical access system using non-orthogonal multiple access multiplexing combined with multi-band carrierless amplitude phase modulation format (NOMA-CAP). Specifically, the SOA has been investigated as both booster and pre-ampli...
Article
Full-text available
The current deployment of 5G networks in a way to support the highly demanding service types defined for 5G, has brought the need for using new techniques to accommodate legacy networks to such requirements. Network Slicing in turn, enables sharing the same underlying physical infrastructure among services with different requirements, thus providin...
Article
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 perf...
Chapter
Network slicing has been taking a major role in upcoming 5G network implementations. However, in order to provision and maintain end-to-end slices, the management and orchestration among different network segments is required. As a result, techniques and components have risen to fulfil these tasks. In this work, we present latency-aware slicing, wh...
Article
Optical switching techniques have the potential to enable the optical data center network (DCN) interconnections providing high capacity and fast switching capabilities, overcoming thus the bandwidth and latency bottleneck of present electrical switch-based multi-tiered DCNs. The rapid growth of multi-tenant applications with heterogeneous traffic...
Conference Paper
Monitoring 3dB bandwidth and other spectrum related parameters at ROADMs provides information about quality of their filters. We propose a machine-learning model to estimate end-to-end filtering penalty for more accurate QoT estimation of future connections.
Conference Paper
Disaggregated DCs offer multiple benefits. However, transmission capacity limitations at blade level can severely degrade their performance. We analyze several strategies to enhance their service acceptance.
Article
Measuring the optical signal to noise ratio (OSNR) at certain network points is essential for failure handling, for single connection but also global network optimization. Estimating OSNR is inherently difficult in dense wavelength routed networks, where connections accumulate noise over different paths and tight filters do not allow the observatio...
Article
This article identifies the unavoidably required upgrade of short-term realizable elastic optical networks (EONs) operating over single-mode fibers toward spectrally-spatially flexible optical networks (SS-FONs), exploiting spatial division multiplexing (SDM) technology in order to cope with the expected mid- and long-term future traffic forecasts....
Conference Paper
We investigate the blocking performance of a dynamic, spectrally and spatially flexible optical network (SS-FON) in which spectral super-channels (SChs) utilizing multiple modulation formats (MFs) are carried over weakly-coupled multi-core fibers (MCFs) and the amount of transceivers (TRX) in network nodes is limited. In the SS-FON scenario conside...
Article
The emergence of new paradigms and services is pushing the limits of nowadays cloud infrastructures. It is a fact that current solutions lack in the flexibility and configurability to adapt to heterogeneous requirements coming from the applications/services to be supported over them. This results most of the time in severe underutilization of the u...
Article
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 migr...
Article
The current constant growth in mobile networks' traffic demands caused by the popularisation of cloud and streaming services on personal devices, requires architectural changes so as to fulfil all new 5G mobile network requirements. Cloud access radio network (C-RAN) architecture in combination with the massive deployment of small cell antenna site...
Conference Paper
We study inter-core crosstalk (ICXT) impact on migration planning toward spectrally-spatially flexible optical networks considering 22-core multi-core fiber. Results reveal, 55-70% of links need to be upgraded when ICXT ranges from -68.2 to-43.4 dB/km.
Article
Full-text available
The use of optical technologies in modern network scenarios has increased in the last decade, mostly due to their support in crucial networking topics (ie, bandwidth and scalability). In parallel, these scenarios have also experienced the emergence of a new paradigm recognized as software‐defined networking (SDN), which bases on the decoupling of f...
Conference Paper
Full-text available
We propose and evaluate a dynamic traffic grooming strategy enhancing the performance of JoS-enabled Flex-Grid/SDM networks. Results disclose up to 120% and 44% additional carried network traffic vs. no grooming and existing end-to-end traffic grooming solutions, respectively.
Conference Paper
We focus on a migration planning from elastic to spectrally-spatially flexible optical networks by upgrading regular with SDM-capable ROADMs. Our most promising strategy reveals that by migrating 30% of the regular ROADMs a 2x carried traffic increase can be achieved.
Conference Paper
Full-text available
The sensitivity performance of an IMDD-OFDM/FBMC/UFMC/GFDM system with a PIN based receiver is experimentally evaluated for downstream in broadband passive optical networks. Results show sensitivities better than-14.5(-8.0)dBm over 50km of SSMF at 5(10)Gbps
Article
Full-text available
The current constant growing in traffic demands caused by the popularization of cloud services, mobile and social networks is requiring architectural changes at the underlying networks so as to provide a more highly dynamic connectivity. Cost-effective and energy efficient solutions are also required in flexible network subsystems in order to make...
Article
Full-text available
In this paper, we target an optimal Multiple-Input Multiple-Output Digital Signal Processing (MIMO-DSP) assignment to super-channels affected by inter-core crosstalk (ICXT) in Multi-Core Fiber (MCF)-enabled transparent optical core networks. MIMO-DSP undoes ICXT effects, but can be costly with high core density MCFs. Hence, its implementation in th...
Article
Future optical core networks realizing Flex-Grid and Space Division Multiplexing (Flex-Grid/SDM) will be key to effectively cope with the rapid growth of the Internet traffic, thanks to their superior capacity and spectrum utilization flexibility. Specifically about SDM, the spatial dimension can be considered either fixed or flexible. The goal of...
Conference Paper
Network slicing has emerged as a major new networking paradigm for meeting the diverse requirements of various vertical businesses in virtualised and softwarised 5G networks. SliceNet is a project of the EU 5G Infrastructure Public Private Partnership (5G PPP) and focuses on network slicing as a cornerstone technology in 5G networks, and addresses...
Article
Full-text available
Space Division Multiplexing (SDM) appears as a promising solution to overcome the capacity limits of single-mode optical fibers. In Flex-Grid/SDM optical networks, nodes offering full interconnection between input/output fiber ports and spatial channels, typical SDM-Reconfigurable Optical Add/Drop Multiplexer (SDM-ROADM) referred to as independent...
Article
Full-text available
Architectural changes are required for 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, to provide a highly dynamic connectivity. Cost-effective and energy-efficient solutions for flexible network subsystems are required to pro...
Article
Space Division Multiplexing (SDM) is a key technology to cope with the bandwidth limitations of single mode fibers. Multi-Core Fibers (MCFs) are considered as a promising candidate technology to implement SDM, due to their low inter-core crosstalk (ICXT), experimentally proven in laboratory prototypes. Among the different channel allocation options...
Conference Paper
Full-text available
The Internet data traffic constant growth caused by the popularization of cloud services, mobile and social networks is requiring changes at the underlying networks in order to enable scalability whereas supporting a highly dynamic connectivity. Cost-effective and energy efficient solutions for flexible network subsystems are also required in order...
Article
Virtual Data Centre (VDC) allocation requires the provisioning of both computing and network resources. Their joint provisioning allows for an optimal utilization of the physical Data Centre (DC) infrastructure resources. However, traditional DCs can suffer from computing resource underutilization due to the rigid capacity configurations of the ser...
Conference Paper
Full-text available
The majority of the research studies on Flex-Grid over multi-core fiber (Flex-Grid/MCF) networks are built on the assumption of fully non-blocking ROADMs (FNB-ROADMs), able to switch any portion of the spectrum from any input core of any input fiber to any output core of any output fiber. Such flexibility comes at an enormous extra hardware cost. I...
Conference Paper
We quantify the network capacity scaling from 7 to 30 spatial channels. While multi-fiber provides a 5x capacity increase, MCF limits it to 4x and 2x in national and continental backbone networks, respectively.
Conference Paper
An integrated software stack made up of extended OpenStack, OpenDaylight and custom OpenFlow agents enabling Virtual Data Centre deployment on an all-optical architecture employing hollow-core fibre, TDM fast switches and a circuit switched backplane.