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The Cooperative Intelligent Transportation System (C-ITS) testbed or simplified called the Smart Highway (Antwerp, Belgium) is designed to facilitate research in the area of distributed/edge computing and vehicular communications. The Smart Highway testbed deploys the Cooperative Awareness Basic Service to exchange Cooperative Awareness Messages (CAMs) between road C-ITS entities, e.g., C-ITS vehicles and Road-Side Units (RSUs). CAMs support vehicular safety and traffic efficiency applications by providing them with the continuous status information of relevant C-ITS entities. Therefore, it is important that those messages are delivered with low latency, especially the CAMs that originate from special vehicles, e.g., emergency vehicles, police cars, and fire trucks. In this paper, we research the impact of CAM messages configuration on the communication latency among vehicles. Moreover, we have performed the practical experimentation to evaluate the aforementioned impact, using ITSG5 and LTE-V2X system under realistic vehicular conditions, on the Smart Highway testbed located in Antwerp.

Cooperative Intelligent Transportation Systems (CITS) deploy the Cooperative Awareness Basic Service to exchange Cooperative Awareness Messages (CAMs) among road C-ITS entities, e.g., vehicles and roadside units (RSUs). CAMs support vehicular safety and traffic efficiency applications that require continuous status information of surrounding C-ITS entities. These messages provide awareness of traffic information in the Non-Line of Sight (NLOS) of the vehicle and are an essential feature to guarantee safety in vehicles. Typically, applications to display CAMs depend on specific C-ITS hardware and software, which implies that each researcher and the industry must develop an application in software and hardware. In this paper, we propose a framework to support research on CAMs through a monitoring dashboard, deploying a portable environment named CAM Application Framework (CAMAF); it manages the received CAMs and updates a corresponding specific monitor for each active C-ITS entity. Each monitor is configurable by choosing CAM fields and making or changing algorithms to display the desired information. We have tested our proposal in a C-ITS testbed with real live traffic.

Along with an increased interest for connected vehicles and autonomous driving, the Cooperative Intelligent Transportation Systems (C-ITS) are being investigated and validated through the use of C-ITS messages, such as Cooperative Awareness Messages (CAMs). In this paper we demonstrate a tool to support research on CAMs, since C-ITS deploy the Cooperative Awareness Basic Service to exchange CAMs among road C-ITS entities, e.g., vehicles and roadside units (RSUs). These messages provide awareness of traffic information in the Non-line-of-sight (NLOS) of the vehicle (e.g., speed, location, heading), and are an enabler of improving safety in vehicles. Therefore, it is important that those messages are received at the receiving C-ITS vehicle with low latency. In this demo, we showcase how the size of a particular CAM that carries information about the vehicle and surrounding infrastructure affects the latency. In order to demonstrate this effect, we use two leading technologies that support the first generation V2X communication respectively ITS-G5 (IEEE 802.11p) and LTE-V2X (3GGP). We have tested our proposal in a real life C-ITS testbed, at the Smart Highway located in Antwerp, Belgium.

Network slicing plays a key role in supporting the influx of smart devices and ensuring their connectivity, because it divides the network into different logical slices over the same shared infrastructure with the aim to guaranty Quality of Service (QoS), security and isolation, which are some of the challenges that IoT systems face. The aim of this paper is to research the possibilities using Network Slicing (NS) towards enabling healthcare services with secured data flows from smart devices to cloud and then back to end user, assuring security, isolation and the required levels of QoS. In this paper, we present the study of: i) isolation and security of network slices, which is important due to interference that occur between slices and can effect the data privacy, ii) service requirements, such as e.g., latency requirement for healthcare services, which is important to have an efficient diagnosis and rapid decisions in case of any risk, and iii) building a hybrid network slicing system, combining different technologies and applying slicing, which could bring the optimal solution for end-to-end for smart healthcare and smart living.

Fog and edge computing paradigms were adopted to enable Internet of Things (IoT) applications, improving response time and reducing network load. Task allocation algorithms are used on IoT-enabled networks to determine the optimal software placement. However, managing such a network is considerably more complex than allocating the tasks. To simplify management, we propose a general Monitor - Analyze - Plan - Execute over a Knowledge base (MAPE-K) framework in which all requirements for task allocation are fulfilled, and where components can easily be adapted to the use case at hand. This research identifies several pitfalls and proposes solutions. Additionally, we apply this approach to a distributed testbed, comparing it to traditional cloud approaches.

Precise time synchronization amongst network devices is a basic requirement for time critical applications. Despite that time synchronization is a well-established functionality in the wired network domain, its wireless counterpart is very basic or even non-existing. This is because commercial off-the-shelf (COTS) wireless chipsets still focus on basic network connectivity for consumer applications, hence no dedicated software/hardware features are required for time-bounded services in professional wireless environments. This work leverages on openwifi - an opensource Wi-Fi chip design based on Software-Defined Radio (SDR), by adding the support of hardware timestamping in openwifi to support precise time protocol (PTP) application. In addition, openwifi Access Point (AP) is connected to nodes in wired network through a TSN capable switch, and synchronization offset between devices in wired and wireless network is measured. Next, the measurement is done with the same setup in wired network but replacing openwifi by COTS Wi-Fi devices. We observe the synchronization offset with COTS is 10 4 fold larger than the offset achieved with openwifi. The experiment setup is in w-iLab.t, an open testbed infrastructure freely accessible for the academic wireless research community.

5G systems promise to enable autonomous vehicles by empowering road-, water-, and air-vehicles with ultra low latency communications and computing at edge in order to share and process data from multiple sensors. However, in order to realize such fully Connected and Automated Mobility (CAM) for cars, drones and vessels, a crucial intermediary step must be fully achieved: 5G-based tele-operated transport. In order to do so, the European project H2020 5G-Blueprint aims to design, test, and validate in real deployments a 5G-enabled tele-operated transport and its enabling functions in both a relevant and operational environment realised through cross-border trials on the road and on the water along 5G corridors in the Dutch and Belgian border area, resulting in a blueprint for future cooperation on 5G-enabled CAM between public, private and semi-private parties (e.g. ports), gaining new and innovative insights on the stringent particular requirements for safe CAM, on the architecture, on governance and relevant business models.

A variety of nanoscale applications require downlink and broadcast-based transmission of control packets from a powered transmitter to energy-harvesting nanonodes with constrained storage capacity. The nanonode's communication system is anticipated to be a bottleneck for such nanonetworks, hence an accurate modeling of its energy consumption is needed. Currently, TS-OOK is a prevailing scheme for nanocommunication in the terahertz (THz) frequencies, with short pulses representing logical "1"s and silences logical "0"s. In the energy modeling of this scheme, certain energy consumptions are attributed to the transmission and reception of the pulses. However, traditional communication systems teach us that the idling energy consumption should not be neglected. Hence, we provide an energy consumption model for TS-OOK-based nanocommunication systems that accounts for the energy consumed in idling, in addition to the transmission and reception-originated consumptions. We demonstrate that, for a meaningful performance of the considered nanonetwork, the nanonode's idling energy consumption has to be at least nine orders of magnitude lower than the corresponding energy consumption in reception. To increase the tolerable idling energy, we propose a new energy lifecycle for the receiving nanonodes. Assuming frequent packet repetitions on the transmit side, the proposed lifecycle utilizes periodic short wake-ups of the receiving nanonodes. We show that, when the proposed lifecycle is utilized, up to three orders of magnitude higher idling energy consumption can be tolerated compared to the baseline.

Electromagnetic nanonetworks operating in the terahertz (THz) frequency band are emerging as a promising technology for supporting a variety of nanoscale applications. At such scales, the use of batteries is in many cases infeasible, thus the nanonodes are envisioned to operate using only capacitors that rely on energy harvesting. This will result in constrained energy storage capacity with unpredictable charging rate, which will in turn yield non-periodic intermittent on-off behavior of the nanonodes. This paradigm is currently largely unexplored, hence it is challenging to make claims about the achievable network reliability. To provide initial insights, we investigate the reliability of nanoscale THz communication in a one-hop downlink broadcast scenario in face of intermittent on-off behavior of the receiving nanonodes. We do that because we believe that the reliable communication will be highly relevant for software-controlled metamaterial applications. Our results demonstrate the need for intelligent selection of energy levels for turning on and off the battery-less nanonodes. In addition and perhaps counter-intuitively, we demonstrate that the repetitions of packets substantially degrade the reliability of the considered nanonetwork.

Current research in Cooperative Intelligent Trans-port System (C-ITS) is focusing mostly on improving the performance of the link layer technology utilized to enable communication between cars or on methods to make traffic more efficient and, most important, safer. Less attention is instead devoted to non-motorized road users such as pedestrians or cyclists which are often addressed as Vulnerable Road Users, or VRUs. In fact, while today it is fair to assume that the vast majority of VRUs are equipped with a smartphones or in general with devices with wireless connectivity, we cannot also assume that such devices are compatible with the variant of the 802.11 standard employed in C-ITS applications known as 802.11p. This is a significant gap in that it prevents critical safety services available to vehicular road users to be extended also to VRUs. In this paper we propose an edge computing-based approach capable of enabling interoperability between 802.11p networks and standard Wi-Fi networks. A technique known as Beacon stuffing is utilized to forward such messages to the VRU's mobile devices without requiring them to be associated to any network. The proposed system can be easily integrated into off-the-shelf mobile phones and tablets without requiring any root access to the device. We prototype and test the proposed system over the Smart-highway Testbed deployed in Antwerp, Belgium.

Health care is an essential service that uses a great deal of sensitive personal data which has a high black market value being a lucrative target for data theft and ransomware attacks. It is clear that the necessary cybersecurity measures should be in place to ensure the protection of this medical and personal data. This is not a one-shot exercise; a broad range of data protection tools need to be integrated and combined to mitigate a large scala of cybersecurity attacks. The ProTego project has performed research on a set of advanced data protection techniques that can be used by hospital and care centers to protect the sensitive data in their systems. These techniques include data encryption, access control, end-device security and secure network communication. Within this whitepaper, the research contributions of the ProTego project in each of these domains will be discussed. Each of the proposed cybersecurity mitigation tool is aimed at preventing specific cybersecurity risks. Besides the strong security protection offered by this technology, another approach is the modular approach taken in the ProTego project. Since there are no strong dependencies between the individual components, depending on the specific needs of the end-user (e.g., hospital), one can opt to only use a subset of the available ProTego cybersecurity risk mitigation tools. Moreover, although the ProTego project specifically focused on a healthcare settings, the tools presented in this whitepaper can be applied in other settings that require data protection as well.

In this paper we demonstrate a framework to support research on Cooperative Awareness Messages (CAMs) through a monitoring dashboard, deploying a portable environment named CAM Application Framework (CAMAF); it manages the received CAMs and updates a corresponding specific monitor for each active Cooperative Intelligent Transportation System (C-ITS) entity. Each monitor is configurable by choosing CAM fields and making or changing algorithms to display the desired information. We have tested our proposal in a C-ITS testbed with real live traffic in the SmartHighway localted in Antwerp, Belgium.

The next generation of vehicular communications has the potential to interconnect Unmanned Automated Vehicles (UAVs), which are the level 5 autonomous vehicles, with its nearby surroundings including Vulnerable Road Users (VRUs), other UAVs, and roadside infrastructure. Given the increased interest in the demand of autonomous driving and Cooperative Connected and Automated Mobility (CCAM), the future UAVs will be safer through enabling communication between UAVs themselves and with their surroundings e.g., VRUs. Communication between UAVs and VRUs will be needed since VRUs will not be able to make a physical eye-contact with the UAVs since their is no physical driver anymore behind the steering wheel. In this way the VRUs can make themselves digitally aware in the UAV traffic and vice versa. Such that UAVs will not be isolated black boxes, i.e., operating and relying fully on their embedded sensors, to its surrounding UAVs and VRUs. This paper shows the current and future needs for autonomous vehicular communication between UAVs and VRUs. Therefore, we present the current trends in the vehicular communication domain and its research challenges. We propose a solution to enable communication between semi-autonomous vehicles, UAVs and their surrounding e.g., VRUs. In our paper, we provide also an early initial proposal to fuse the Vehicle-to-everything (V2X) communication with the embedded autonomous software in the autonomous vehicle.

Intelligent edge orchestration has become a vital component within next generation communication networks, such as 5G. They offer optimal resource allocation and service distribution, hence allow for full utilization of the opportunities provided by those networks. Orchestrators make use of Machine Learning (ML) techniques to determine the most optimal operational decisions, such as deployment and scaling of services, ensuring the quality of the service performance. The training and validation of these models require significant amount of data. However, in such environments we deal with heterogeneous and distributed data sources, in which the data needs to be collected and pre-processed efficiently, and as such, made ready-to-use for these ML models. Hence, in this paper several state-of-the-art data management technologies suitable for edge computing and orchestration are investigated and compared. After investigating the theoretical features of these technologies, they are deployed and tested on the Smart Highway testbed. The strengths and shortcomings of these systems are presented and compared based on the Quality of Service (QoS) requirements for various vehicular services dealing with highly mobile users, i.e., vehicles, which are considered as quite stringent. This hybrid platform, combining several data management technologies, will be used to assist and enrich the research on smart edge orchestration at IDLab and serve as a reference for other interested parties.

Part 1: Regular Papers; International audience; Next generation networks – spanning from wide area networks to intra-datacenters – are expected to encompass devices and sub-devices from different vendors. Inter operability and vendor neutrality are now key topics for researchers and companies as a way to reduce costs avoiding to be tied to a single vendor. Also the management system is expected to be disaggregated from the hardware and possibly developed by a different company. An example is the white box, which disaggregates the software from the hardware and can be composed of modules from different vendors. Currently, NETCONF – based on YANG – is the protocol considered for the (re)configuration of white boxes. Discussions are being carried on to identify commonly agreed information models to guarantee vendor-neutral configuration and management of next generation networks.In addition, emerging services (e.g., 5G) will impose the involvement of a variety of technologies (e.g., networks, datacenters) and resources (e.g., compute, storage, radio). Such heterogeneity will imply the cooperation of several business actors to bring services to the users. In such a scenario, the management of resources will require their abstraction in order to satisfy confidentiality as well as to increase scalability and, again, to provide information that is neutral with respect to the related vendor and technology.In this paper, we propose to use NETCONF also for the exchange of resource information among different business actors considering the several network segments (wide area network, data centers, radio segment) involved in a 5G vertical. To this purpose, resource abstraction is proposed based on a YANG data model. An experiment will involve the (re)configuration of a wide area network composed of white boxes. Moreover, resource information (virtual links) will be exchanged through NETCONF with the objective of orchestrating resources.

Part 1: Regular Papers; International audience; Spectrally-spatially flexible optical networks (SS-FONs) are proposed as a solution for future traffic requirements in optical backbone networks. As SS-FONs operate within flex-grid, the provisioning of lightpaths spanning multiple frequency slots results in spectrum fragmentation, especially in presence of dynamic traffic. Fragmentation, in turn, may lead to blocking of dynamic requests due to the lack of sufficiently-large free spectral windows. In this paper, to reach a better understanding of fragmentation in SS-FON, we extend several metrics used in (single-core) elastic optical networks to measure the fragmentation in SS-FONs. Next, we apply these metrics to a dynamic-routing algorithm with the goal of minimizing bandwidth blocking. Finally, we analyze the impact of spatial continuity constraint (SCC) on the network fragmentation. Simulations run on two representative network topologies show that the root mean square factor metric yields the best performance in terms of blocking when compared to other analyzed metrics.

Part 1: Regular Papers; International audience; The FASTER cable system has been developed as the first trans-pacific optical submarine cable system designed for digital-coherent transmission at the initial state. With this significant change for submarine cables, the design capacity is continuously being upgraded following the improvement of the state-of-the-art modulation format to maximize spectral efficiency even at the limited optical signal-to-noise ratio (OSNR). For the next generation, the novel technologies are expected to increase the capacity per cable under the conditions of limited feeding power and space in a cable. This report reviews some technologies from the current to the promising future submarine cable systems such as the introduction of space-division-multiplexing (SDM) technologies.

Part 1: Regular Papers; International audience; Network resources are imperfect and vulnerable to failure from a wide variety of sources. Survivability is a well-researched field that focuses on strategies to prevent or reduce the harm inflicted when network elements fail. Solutions tend to either provision resources, such as backup paths, proactively so that traffic can be switched to the alternative route after a failure, or quickly find new resources to provision after failure event occurs. Current survivability solutions guarantee protection against these failures, but there is no mathematical model to calculate the network blocking probability for survivability solutions of anycast communication. In this paper, we developed new analytical models to calculate network-wide blocking performance for anycast survivability approaches. Performance results show that our models are accurate and are verified by extensive simulation results.

Part 2: Poster Papers; International audience; It is generally very difficult to optimize the routing policies in optical networks with dynamic traffic. Most widely-used routing policies, e.g., shortest path routing and least congested path (LCP) routing, are heuristic policies. Although the LCP is often regarded as the best-performing adaptive routing policy, we are often eager to know whether there exist better routing policies that surpass these heuristics in performance. In this paper, we propose a framework of reinforcement learning (RL) based routing scheme, that learns routing decisions during the interactions with the environment. With a proposed self-learning method, the RL agent can improve its routing policy continuously. Simulations on a ring-topology metro optical network demonstrate that, the proposed scheme outperforms the LCP routing policy.

Part 2: Poster Papers; International audience; Advanced interconnect technologies play a prominent role in scaling up the performance of data center networks. Spatial Division Multiplexing (SDM) photonic interconnects have been suggested as means to overcome capacity upgrade requirements and enable disaggregation in future data centers. Here, Holographic Optical Elements (HOE) are proposed for SDM photonic interconnects. The proposed coupling scheme entails the use of holograms as fan out components for coupling light from a source to multicore fibers (MCF). The scheme is versatile and can be adopted to any SDM fiber core arrangement. Appropriate Computer-Generated Holograms (CGHs) are designed for two kind of MCF and the HOE interconnect is evaluated in terms of performance variations against system and fabrication related parameters. Furthermore, the interconnect design is optimized for loss-sensitive applications.

Part 2: Poster Papers; International audience; In this paper, we propose a stochastic failure and optical network topology (SFONT) model that can be used to comprehensively analyze the resilience of optical networks against a large number of possible earthquakes. We study an optical network densification problem, where dense network topologies are generated using the proposed SFONT model. Further, a seismic-risk aware optical network densification (SRA-OND) scheme is proposed with a view to design the future optical networks robust against earthquakes. The proposed SFONT model has been evaluated at various stages of network densification. To validate the capability of the proposed SFONT model to emulate real-world networking and failure scenario, we also perform a similar analysis based on RailTel optical network topology, seismic hazard maps, and real past earthquake data from India. Simulations indicate that the proposed SFONT model can be used to estimate and analyze the impact of network-resilience schemes on optical networks for a large number of possible earthquakes.

Part 1: Regular Papers; International audience; In optical transport networks, the Quality of Transmission (QoT) using a physical layer model (PLM) is estimated before establishing new or reconfiguring established optical connections. Traditionally, high margins are added to account for the model’s inaccuracy and the uncertainty in the current and evolving physical layer conditions, targeting uninterrupted operation for several years, until the end-of-life (EOL). Reducing the margins increases network efficiency but requires accurate QoT estimation. We present two machine learning (ML) assisted QoT estimators that leverage monitoring data of existing connections to understand the actual physical layer conditions and achieve high estimation accuracy. We then quantify the benefits of planning/upgrading a network over multiple periods with accurate QoT estimation as opposed to planning with EOL margins.

Part 2: Poster Papers; International audience; Machine learning techniques for optimization purposes in the optical domain have been reviewed extensively in recent years. While several studies are pointing in the right direction towards building enhanced transport network control systems including estimation algorithms, the physical effects encountered in the optical domain raise several challenges that are hard to learn from and mitigate. In this paper, we provide a performance analysis of various supervised learning algorithms when predicting the Quality of Transmission (QoT), in terms of signal to noise ratio (OSNR), of lightpaths when erbium doped fiber amplifier (EDFA) power excursions and fiber nonlinearities are taken into account. The analysis considers F1-scores and computational training times as the main comparison metrics. A customized optical data network simulator was used for the generation of synthetic labeled data samples. Our results depict similar performance among groups of classifiers, and a correlation between the data sample size and the prediction accuracy.

Part 1: Regular Papers; International audience; The transmission reach of multi-core fiber (MCF) communication systems is severely affected by inter-core crosstalk (IC-XT), which limits its application for long-reach core optical network. One of the major factors limiting the transmission reach of MCF is nonlinear IC-XT interference, which makes the overall system nonlinear, thereby resulting in a poor bit error rate (BER) performance. Conventional Volterra series based nonlinear equalizer are computationally complex, and impaired by modeling error due to the truncation of polynomial kernel. In this paper, for the first time, we propose multivariate kernel least mean square (KLMS) based adaptive nonlinear equalizer for mitigating IC-XT impairments in MCF communication systems. The proposed scheme is inspired from reproducing kernel Hilbert space (RKHS) based machine learning algorithms. Simulations are performed for different multi-core structures, fiber lengths, and modulation schemes, which show that the proposed KLMS algorithm exhibit superior BER performance over the existing Volterra series equalizer.

Part 1: Regular Papers; International audience; We review the most important WDM DCI system innovations. State-of-the-art coherent transmission has already exceeded 6 b/s/Hz, using subcarrier modulation. The adoption of software innovations in automation and programmability, that DCI pioneered in transport networks, has also simplified operations and enables the emergence of “open” transport architectures. Combining these advancements with emerging network analytics frameworks allows exciting innovations in network design and management optimization.

Part 1: Regular Papers; International audience; Parallel computing allows us to process incredible amounts of data in a timely manner by distributing the workload across multiple nodes and executing computation simultaneously. However, the performance of this parallelism usually suffers from network bottleneck. In optical switching enabled data center networks (DCNs), to satisfy the complex and time-varying bandwidth demands from the parallel computing, it is critical to fully exploit the flexibility of optical networks and meanwhile reasonably schedule the optical resources. Considering that the traffic flows generated by different applications in DCNs usually exhibit different statistical or correlative features, it is promising to schedule the optical resources with the assistance of machine learning. In this paper, we introduce a framework called intelligent optical resources scheduling system, and discuss how this framework can assist resource scheduling based on machine learning approaches. We also present our recent simulation results to verify the performance of the framework.

Part 1: Regular Papers; International audience; We present a review of photonic Network-on-Chip (pNoC) architectures and experimental demonstrations, concluding to the main obstacles that still impede the materialization of these concepts. We also propose the employment of optics in chip-to-chip (C2C) computing architectures rather than on-chip layouts towards reaping their benefits while avoiding technology limitations on the way to many-core set-ups. We identify multisocket boards as the most prominent application area and present recent advances in optically enabled multisocket boards, revealing successful 40 Gb/s transceiver and routing capabilities via integrated photonics. These results indicate the potential to bring energy consumption down by more than 60% compared to current QuickPath Interconnect (QPI) protocol, while turning multisocket architectures into a single-hop low-latency setup for even more than 4 interconnected sockets, which form currently the electronic baseline.

Part 1: Regular Papers; International audience; This study focuses on the provisioning of resilient Cloud Radio Access Network (C-RAN) services employing optical transport networks. In response to the high bandwidth requirements necessary for the protection of the C-RAN architecture from optical transport network and/or BBU failures, a novel approach based on Network Coding (NC) is proposed. A novel architectural and hardware framework to enable NC are also provided and a suitable implementation addressing the problem of fast NC-related operations processing at the edge is demonstrated. A global time stamping solution that can be used to address the strict synchronization requirements of FH flows arriving at the BBUs, keeping buffering at the edge as low as possible, has been developed. The performance of the proposed solution has been experimentally evaluated demonstrating negligible penalties. Network level modeling results demonstrate a reduction of the total optical network capacity required for this type of applications by 33%.

Part 1: Regular Papers; International audience; Next generation fronthaul interface has been recently proposed to support different functional splits in 5G access networks. Each split option is characterized by different requirements in terms of latency and bandwidth. The mapping of different functional splits on the nodes of 5G access network introduces several degrees of freedom in relation to the variation of the traffic during the day. This paper proposes a novel function location algorithm, which adopts dynamic function chaining in relation to the evolution of the traffic estimate. The obtained results show remarkable improvement in terms of bandwidth saving and multiplexing gain with respect to conventional C-RAN fronthaul and suggest design criteria for the emerging 5G access network.

Part 1: Regular Papers; International audience; The ability to assign functions that comprise the BBU processing in centralized softwarised Radio Access Networks into different servers the, have been proven to be beneficial, in terms of energy efficiency. This paper proposes a heuristic suitable for BBU functions allocation and evaluates the impact of dynamic resource management in these environments facilitated through Virtual Machine (VM) live migration. The benefits associated with VM migration are quantified through a series of experiments. Our results show notable improvement in terms of resource and energy efficiency.

Most deployed optical transport networks are proprietary, behaving as a closed, highly coupled, single-vendor managed domain. Although their control planes and management systems may export high-level and open northbound interfaces (NBI), the internal details and interfaces are not disclosed to the network operator. However, driven by the requirements of telecommunication and datacenter operators and the need to keep costs down while supporting sustained traffic increase, a trend known as disaggregation has steadily emerged during the past years. It involves composing and assembling open and available components, devices and sub-systems into optical infrastructures and networks, combining “best-in-class” devices, tailored to the specific needs of the aforementioned operators. It has been motivated by factors such as an increase in hardware commoditization, a perceived different rate of innovation of the different components, a promised acceleration in service deployment, or the consequent reduction in operational and capacity expenses. In practice, disaggregation brings multiple challenges, depending on the level that applies (e.g., partial or total, down to each of the optical components) and is taking place in stages. It is commonly accepted that disaggregation implies a trade-off between: i) the opportunities due to the new degree of flexibility provided by component migration and upgrades without vendor lock-in and ii) the potential decrease in performance compared to fully integrated systems and the underlying complexity – including interoperainteroperability-, critical in full disaggregation scenarios. From the point of view of control and management, disaggregation heavily relies on the adoption of open interfaces exporting hardware programmability. Disaggregated optical networks are an important use case for the adoption or a unified, model-driven development. In this paper, tutorial in nature, we will introduce the main concepts behind Software Defined Networking (SDN) for disaggregated optical networks, presenting reference architectures and industry common practices related to the adoption of a unified, model driven approach. The second part will cover an overview of selected deployment models (e.g., addressing transceiver and OLS disaggregation) as well as the OpenConfig and OpenROADM optical device models and Transport API (TAPI) interfaces, which constitute the main elements of the implemented SDN control plane. Such control plane targets mainly the metro segment, as defined within the EC Metro-Haul and ONF ODTN projects., Grant numbers : Experimental research testbed on high-performance and large-scale intelligent optical transport networks.

Part 2: Poster Papers; International audience; In this work, we exploit the spatial dimension of spectrally-spatially flexible optical networks (SS-FONs) to perform path selection. The existing path selection schemes in SS-FONs predominantly use k-shortest paths (KSP) method. However, in this work, we demonstrate that in SS-FONs, consideration of core selection along with link selection between source and destination nodes can significantly increase the spectrum utilization efficiency. We propose a k-core arrangement based paths (KCAP) scheme that performs path calculation and prioritization on the basis of core arrangement in different multicore fiber (MCF) structures, threshold crosstalk (XT) values, distance adaptive modulation (DAM), and the number of MCF links. The proposed KCAP achieves better spectrum utilization than the existing XT-aware and predefined core-prioritization schemes.

Part 1: Regular Papers; International audience; We experimentally demonstrate two Analog Mobile Fronthaul concepts exploiting coherent optical systems technology. Single Sideband generation and coherent detection of a 12 Gb/s signal with 6 subcarriers using an IQ modulator is presented along with an extended reach Fiber-Wireless transmission concept using IQM-DD system and V-band radio.

Part 1: Regular Papers; International audience; The concept of edge computing is vital in the 5G ecosystem, as a means of introducing application awareness in the network and enabling constructs such as slicing to be effectively implemented. In this scope, an efficient infrastructure dimensioning requires visibility of both network and data-center resources. While this joint optimization is becoming increasingly common even at the optical layer, some aspects of the dimensioning remain siloed between the network/IT worlds. Survivability mechanisms are one such example, where protection for lightpaths and/or virtual network functions (VNFs) is typically provisioned independently, potentially incurring in resource overprovisioning. This paper investigates the merits of exploiting a hybrid strategy where backup resources are selectively distributed between the IT and optical layers in metro ring scenarios, according to specific service requirements such as latency and bandwidth. Critically, this analysis incorporates, through an integer linear programming (ILP) model, the effect of optical path performance on the cost efficiency of protection mechanisms, which is shown to greatly influence the optimal resource distribution in each deployment scenario.

Part 1: Regular Papers; International audience; A wireless-optical broadband access network (WOBAN) shows promise as potential 5G access infrastructure. Since network slicing allows efficient sharing of physical network resources, we consider the provisioning of availability-guaranteed slices in a WOBAN supporting mobile edge computing (MEC). A new definition for the availability of a slice is proposed accounting for a slice that functions only partially because of the failure of a fiber link, a microwave link, a base station (BS) node, and/or an optical line terminal (OLT). An integer linear programming (ILP) model and a simple but effective heuristic algorithm that balances the network traffic load and maximizes the slice availability are developed to maximally provision availability-guaranteed slices. Simulation results show the efficiency of the proposed approaches.

Part 1: Regular Papers; International audience; Passive Optical Networks (PONs) are an economically efficient means of providing high bandwidth services to end users because end-points can share the cost and the benefit of fibre optic connection. There is a growing interest in the use of PONs as a bearer for services such as Long Term Evolution (LTE), however work remains to be done to ensure stable, low latency and low packet loss for full duplex Transmission. In this paper we are mostly concerned with the characteristics of the downstream channel so as to further the case for PON sharing. We review typical downstream schedulers used in the industry and propose a three-stage downstream scheduler that assures quality of service, accurately, across Virtual Network Operators (VNOs) in multi-tenant PONs environment. We benchmark our scheduler against other algorithms, obtaining almost ideal scheduling performance.

Part 1: Regular Papers; International audience; Emerging inter-datacenter applications involving data transferred, processed, and analyzed at multiple data centers, such as virtual machine migrations, real-time data backup, remote desktop, and virtual data centers, can be modeled as virtual network requests that share computing and spectrum resources of a common substrate physical inter-datacenter network. Recent advances make flexible optical networks an ideal candidate for meeting the dynamic and heterogeneous connection demands between datacenters. In this paper, we address the static (offline) version of the virtual network embedding problem in flexible optical networks equipped with sliceable bandwidth variable transponders (SBVTs). The objective is to minimize the total number of required SBVTs in the network. An Integer Linear Programming (ILP) formulation is presented, lower bounds are derived, and four heuristics are proposed and compared. Simulation results are presented to show the effectiveness of the proposed approaches.

Part 1: Regular Papers; International audience; The introduction of all-optical switching in data center interconnection networks (DCN) is key to addressing some of the shortcomings of state-of-the-art electronic switched solutions. Limitations in the port count, reconfiguration speed and cost of optical switches, however, require novel optical switching and DCN designs. We present the concept of a simplified DCN fabric that relies on a lean optical switch design of limited but scalable functionality that offers high reconfiguration speeds, real-time scheduling, efficient control and low equipment cost. To achieve these objectives, the proposed architecture relaxes the usual non-blocking switching requirements but opts for switching modules that are constrained in terms of the achievable space and wavelength input-output configurations. We analytically compare the functionality and complexity of the simplified fabric with those of a non-blocking switch. We evaluate the throughput performance of the simplified DCN fabric and compare it to that of other fabrics with a different level of functionality and centralized control.

Part 1: Regular Papers; International audience; An overview of the current status of the EU Metro-Haul project and its impact on 5G End to End KPIs together with a summary of the use cases and demonstrations intended to illustrate the technology being developed.

Part 2: Poster Papers; International audience; The traffic in today’s transport networks is increasing dramatically due to more demanding applications like video on demand and improving access technologies like 5G. Additionally, the quality of service requirements are becoming more stringent while network operators are seeking new ways for revenue creation. We propose a multi-layer network reconfiguration approach that reduces the overfulfillment of service delay requirements. In that way it provides an incentive to customers with low-delay services to acquire a more expensive service class for their traffic. Additionally, it relieves highly utilized links for services with very strict delay requirements. We provide an ILP formulation that solves this multi-layer network problem by performing a cross-layer optimization. Further, we evaluate our approach for two nationwide backbone networks. We show that a reduction of service delay overfulfillment is possible and how that affects other network metrics.

Part 1: Regular Papers; International audience; Optical multi-domain transport networks are often controlled by a hierarchical distributed architecture of controllers. Optimal placement of these controllers is very important for their efficient management and control. Traditional SDN controller placement methods focus mostly on controller placement in datacenter networks. But the problem of virtualized controller placement for multi-domain transport networks needs to be solved in the context of geographically-distributed heterogeneous multi-domain networks. In this context, Edge Datacenters have enabled network operators to place virtualized controller instances closer to users, besides providing more candidate locations for controller placement. In this study, we propose a dynamic controller placement method for optical transport networks that considers the heterogeneity of optical controllers, resource limitations at edge hosting locations, latency requirements, and costs. Simulation studies considering practical scenarios show significant cost savings and delay reductions compared to standard placement approaches.

Part 2: Poster Papers; International audience; Underwater optical wireless communications (UOWC) have gained attention due to the advantages they offer that can greatly alter the performance of a link. But such systems are affected by absorption and non predictable factors that may decrease the availability and the reliability of the system. In this work, the bit error rate (BER) of an underwater optical link with heterodyne detection modulated with M-QAM technique in presence of turbulence and pointing errors will be investigated. This investigation will lead to a closed form mathematical expression for the BER as a function of link parameters, that is very important in order to deploy an effective link. Various numerical results will also be presented for the reliability of the system.

Part 2: Poster Papers; International audience; Multicore fibers can be used for Radio over Fiber transmission of mmwave signals for phased array antennas in 5G networks. The inter-core skew of these fibers distorts the radiation pattern and has to be measured and compensated. We propose a method to accurately measure the differential delays remotely, after installation, without intervening heavily with the transmitter setup. The properties of the phase response measured at a distant receiver are exploited to acquire the differential delays among the antenna array elements.